#pragma GCC optimize("O3")
//By SiriusRen
#include <bits/stdc++.h>
using namespace std;
const int N=100500;
typedef long long ll;
int n,m,xx,yy,first[N],next[N*2],v[N*2],tot;
int in[N],out[N],deep[N],p[N],f[N][19],cnt,lazy[N*4];
int fa[N],ch[N][2],rev[N],q[N],top,root;
ll sum[N*4];char op[10];
void add(int x,int y){v[tot]=y,next[tot]=first[x],first[x]=tot++;}
void dfs(int x){in[x]=++cnt,p[cnt]=x;for(int i=first[x];~i;i=next[i])if(!deep[v[i]])deep[v[i]]=deep[x]+1,f[v[i]][0]=x,fa[v[i]]=x,dfs(v[i]);out[x]=cnt;
}
int lca(int x,int y){if(deep[x]<deep[y])swap(x,y);for(int i=16;~i;i--)if(deep[f[x][i]]>=deep[y])x=f[x][i];if(x==y)return x;for(int i=16;~i;i--)if(f[x][i]!=f[y][i])x=f[x][i],y=f[y][i];return f[x][0];
}
int _lca(int x,int y){for(int i=16;~i;i--)if(deep[f[x][i]]>deep[y])x=f[x][i];return x;}
void pushup(int pos){sum[pos]=sum[pos<<1]+sum[pos<<1|1];}
void pushdown(int l,int r,int pos){int mid=(l+r)>>1,lson=pos<<1,rson=pos<<1|1;lazy[lson]+=lazy[pos],sum[lson]+=1ll*(mid-l+1)*lazy[pos];lazy[rson]+=lazy[pos],sum[rson]+=1ll*(r-mid)*lazy[pos];lazy[pos]=0;
}
void build(int l,int r,int pos){if(l==r){sum[pos]=deep[p[l]];return;}int mid=(l+r)>>1,lson=pos<<1,rson=pos<<1|1;build(l,mid,lson),build(mid+1,r,rson),pushup(pos);
}
void insert(int l,int r,int pos,int L,int R,int wei){if(l>=L&&r<=R){lazy[pos]+=wei;sum[pos]+=1ll*wei*(r-l+1);return;}if(lazy[pos])pushdown(l,r,pos);int mid=(l+r)>>1,lson=pos<<1,rson=pos<<1|1;if(mid<L)insert(mid+1,r,rson,L,R,wei);else if(mid>=R)insert(l,mid,lson,L,R,wei);else insert(l,mid,lson,L,R,wei),insert(mid+1,r,rson,L,R,wei);pushup(pos);
}
ll query(int l,int r,int pos,int L,int R){if(l>=L&&r<=R)return sum[pos];if(lazy[pos])pushdown(l,r,pos);int mid=(l+r)>>1,lson=pos<<1,rson=pos<<1|1;if(mid<L)return query(mid+1,r,rson,L,R);else if(mid>=R)return query(l,mid,lson,L,R);else return query(l,mid,lson,L,R)+query(mid+1,r,rson,L,R);
}
bool isroot(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;}
void rotate(int p){int q=fa[p],y=fa[q],x=(ch[q][1]==p);ch[q][x]=ch[p][!x],fa[ch[q][x]]=q;ch[p][!x]=q,fa[p]=y;if(!isroot(q)){if(ch[y][1]==q)ch[y][1]=p;if(ch[y][0]==q)ch[y][0]=p;}fa[q]=p;
}
void push_down(int x){if(rev[x])rev[ch[x][0]]^=1,rev[ch[x][1]]^=1,swap(ch[x][0],ch[x][1]),rev[x]=0;}
void Pushdown(int x){q[++top]=x;for(int i=x;!isroot(i);i=fa[i])q[++top]=fa[i];while(top)push_down(q[top]),top--;
}
void splay(int x){Pushdown(x);for(int y=fa[x];!isroot(x);rotate(x),y=fa[x])if(!isroot(y)){if((ch[fa[y]][0]==y)^(ch[y][0]==x))rotate(x);else rotate(y);}
}
void find(int x,int y){Pushdown(x);while(ch[x][0])x=ch[x][0],Pushdown(x);if(x==root)insert(1,n,1,1,n,y);else if(lca(x,root)!=x)insert(1,n,1,in[x],out[x],y);else{int t1=_lca(root,x);if(in[t1]^1)insert(1,n,1,1,in[t1]-1,y);if(out[t1]^n)insert(1,n,1,out[t1]+1,n,y);}
}
void access(int x){for(int t=0;x;ch[x][1]=t,t=x,x=fa[x]){splay(x);if(ch[x][1])find(ch[x][1],1);if(t)find(t,-1);}
}
void makeroot(int x){access(x),splay(x),rev[x]^=1,root=x;}
ll Query(int x,int k){if(x==root)return k?n:query(1,n,1,1,n);if(lca(x,root)!=x)return k?out[x]-in[x]+1:query(1,n,1,in[x],out[x]);int t1=_lca(root,x);ll r=0;if(in[t1]^1)r=k?in[t1]-1:query(1,n,1,1,in[t1]-1);if(out[t1]^n)r+=k?n-out[t1]:query(1,n,1,out[t1]+1,n);return r;
}
inline int read(){int x=0;char p=getchar();while(p<'0'||p>'9')p=getchar();while(p>='0'&&p<='9')x=x*10+p-'0',p=getchar();return x;
}
int main(){memset(first,-1,sizeof(first));scanf("%d%d",&n,&m);for(int i=1;i<n;i++)xx=read(),yy=read(),add(xx,yy),add(yy,xx);root=deep[1]=1,dfs(1),build(1,n,1);for(int j=1;j<17;j++)for(int i=1;i<=n;i++)f[i][j]=f[f[i][j-1]][j-1];while(m--){scanf("%s",op),xx=read();if(op[2]=='L')access(xx);else if(op[2]=='C')makeroot(xx);else if(op[2]=='Q')printf("%.10f\n",(double)Query(xx,0)/Query(xx,1));}
}

#include <cstdio>
#include <algorithm>
#define M ((L+R)>>1)
#define lc o<<1
#define rc o<<1|1
#define ls lc,L,M
#define rs rc,M+1,R
#define f(x) t[x].p
#define l(x) t[x].s[0]
#define r(x) t[x].s[1]
#define LC(x) (r(f(x))==x)
#define st(a,b,c) t[a].s[b]=c;f(c)=atypedef long long ll;
const int N=100005,B=200005;
char op[9]; int n,m,x,y,e,tt,sd,hd[N],nx[B],to[B],bg[N],ed[N],f[N][17],d[N],p[N],v[N*4]; ll sm[N*4];
struct nd {int p,rv,s[2];}t[N];
void ad(int x,int y) {to[++e]=y,nx[e]=hd[x],hd[x]=e;}void dfs(int x) {bg[x]=++tt,p[tt]=x;for(int i=hd[x];i;i=nx[i]) if(!d[to[i]]) d[to[i]]=d[x]+1,f[to[i]][0]=x,f(to[i])=x,dfs(to[i]);ed[x]=tt;
}
int lca(int x,int y) {if(d[x]<d[y]) std::swap(x,y);for(int i=16;~i;i--) if(d[f[x][i]]>=d[y]) x=f[x][i];if(x==y) return x;for(int i=16;~i;i--) if(f[x][i]^f[y][i]) x=f[x][i],y=f[y][i];return f[x][0];
}
int _lca(int x,int y) {for(int i=16;~i;i--) if(d[f[x][i]]>d[y]) x=f[x][i]; return x;}
void pu(int o) {sm[o]=sm[lc]+sm[rc];}
void bd(int o,int L,int R) {if(L==R) {sm[o]=d[p[L]]; return;}bd(ls),bd(rs),pu(o);
}
void PD(int o,int L,int R) {if(v[o]) v[lc]+=v[o],v[rc]+=v[o],sm[lc]+=(ll)(M-L+1)*v[o],sm[rc]+=(ll)(R-M)*v[o],v[o]=0;}
void upd(int o,int L,int R,int l,int r,int x) {if(l<=L&&r>=R) {v[o]+=x,sm[o]+=(ll)x*(R-L+1); return;}PD(o,L,R);if(l<=M) upd(ls,l,r,x); if(r>M) upd(rs,l,r,x);pu(o);
}
ll qr(int o,int L,int R,int l,int r) {if(l<=L&&r>=R) return sm[o];PD(o,L,R);if(r<=M) return qr(ls,l,r);if(l>M) return qr(rs,l,r);return qr(ls,l,r)+qr(rs,l,r);
}bool rt(int x) {return l(f(x))!=x&&r(f(x))!=x;}
void _pd(int x) {if(t[x].rv) t[l(x)].rv^=1,t[r(x)].rv^=1,std::swap(l(x),r(x)),t[x].rv=0;}
void pd(int x) {if(!rt(x)) pd(f(x)); _pd(x);}
void rot(int x) {int y=f(x),lx=LC(x); st(y,lx,t[x].s[!lx]); if(!rt(y)) st(f(y),LC(y),x); st(x,!lx,y);}
void sp(int x) {pd(x); for(int y=f(x);!rt(x);rot(x),y=f(x)) if(!rt(y)) {if(LC(x)^LC(y)) rot(x); else rot(y);}}
void fd(int x,int y) {_pd(x);while(l(x)) x=l(x),_pd(x);if(x==sd) upd(1,1,n,1,n,y);else if(lca(x,sd)^x) upd(1,1,n,bg[x],ed[x],y);else {int t1=_lca(sd,x);if(bg[t1]^1) upd(1,1,n,1,bg[t1]-1,y);if(ed[t1]^n) upd(1,1,n,ed[t1]+1,n,y);}
}
void acs(int x) {for(int y=0;x;r(x)=y,y=x,x=f(x)) {sp(x);if(r(x)) fd(r(x),1);if(y)fd(y,-1);}
}
void mk(int x) {acs(x),sp(x),t[x].rv^=1,sd=x;}
ll qs(int x,int k) {if(x==sd) return k?n:qr(1,1,n,1,n);if(lca(x,sd)^x) return k?ed[x]-bg[x]+1:qr(1,1,n,bg[x],ed[x]);int t1=_lca(sd,x); ll r=0;if(bg[t1]^1) r=k?bg[t1]-1:qr(1,1,n,1,bg[t1]-1);if(ed[t1]^n) r+=k?n-ed[t1]:qr(1,1,n,ed[t1]+1,n);return r;
}int main() {scanf("%d%d",&n,&m);for(int i=1;i<n;i++) scanf("%d%d",&x,&y),ad(x,y),ad(y,x);sd=d[1]=1,dfs(1),bd(1,1,n);for(int j=1;j<17;j++) for(int i=1;i<=n;i++) f[i][j]=f[f[i][j-1]][j-1];while(m--) {scanf("%s%d",op,&x);if(op[2]=='L') acs(x);else if(op[2]=='C') mk(x);else if(op[2]=='Q') printf("%.10f\n",(double)qs(x,0)/qs(x,1));}return 0;
}

//By SiriusRen
#include <ctime>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define rd (rand()|rand()<<15)
int seed;
const int mod=1000000007;
int main(){freopen("seed.txt","r",stdin);scanf("%d",&seed);srand(seed+time(0));rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();rand();freopen("seed.txt","w",stdout);freopen("in.txt","w",stdout);int n=100000,m=100000;printf("%d %d\n",n,m);for(int i=2;i<=n;i++)printf("%d %d\n",rand()%(i-1)+1,i);for(int i=1;i<=m;i++){int t=rand()%3;if(t==0)printf("RELEASE %d\n",rand()%n+1);else if(t==1)printf("RECENTER %d\n",rand()%n+1);else printf("REQUEST %d\n",rand()%n+1);}
}

//By SiriusRen
#include <ctime>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int cases,xx;
int main(){while(1){printf("case # %d\n",++cases);system("mk.exe");long tim=clock();system("a.exe<in.txt>out1.txt");printf("programme a time=%ld\n",clock()-tim);tim=clock();system("b.exe<in.txt>out2.txt");printf("programme b time=%ld\n",clock()-tim);if(system("fc out1.txt out2.txt")){puts("Wrong Answer");while(1);}printf("Accepted\n\n");}
}