#include<cstdio>
#include<cstring>#define N 100001using namespace std;char s[N];int LAST[26],last[N],pre[N][26],suf[N][26];
bool w[N],c[26];int main()
{freopen("cross.in","r",stdin);freopen("cross.out","w",stdout);scanf("%s",s+1);int len=strlen(s+1),ans=0,ch;for(int i=1;i<=len;i++)for(int j=0;j<26;j++)if(s[i]-'a'==j) pre[i][j]=i;else pre[i][j]=pre[i-1][j];for(int i=0;i<26;i++) suf[len][i]=len+1;suf[len][s[len]-'a']=len;for(int i=len-1;i;i--)for(int j=0;j<26;j++)if(s[i]-'a'==j) suf[i][j]=i;else suf[i][j]=suf[i+1][j];for(int i=1;i<=len;i++){ch=s[i]-'a';c[ch]^=1; w[i]=!c[ch];if(c[ch]) LAST[ch]=i;else last[i]=LAST[ch];}for(int i=1;i<=len;i++)if(w[i]){for(int j=0;j<26;j++)if(j!=s[i]-'a'){if(suf[last[i]][j]<i && w[suf[last[i]][j]]) ans++;if(pre[i][j]>last[i] && !w[pre[i][j]]) ans++;}}printf("%d",ans>>1);
}

#include<queue>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>using namespace std;#define N 501
#define M 2001int n,m,g,k;int front[N],to[M<<1],nxt[M<<1],val[M<<1],tot;
bool fly[M<<1];int DIS[N][2001];struct node
{int tim,dis,num;bool operator < (node p) const{return dis>p.dis;}
}cur,nt;priority_queue<node>q;void read(int &x)
{x=0; char c=getchar();while(!isdigit(c)) c=getchar();while(isdigit(c)) { x=x*10+c-'0'; c=getchar(); }
}void add(int u,int v,int w,bool fl)
{to[++tot]=v; nxt[tot]=front[u]; front[u]=tot; val[tot]=w; fly[tot]=fl;
}void init()
{read(n); read(m); read(g); read(k);int u,v,w;k=min(g,k);while(m--){read(u); read(v); read(w);add(u,v,w,0);}while(g--){read(u); read(v); read(w);add(u,v,w,1);}
}void dijkstra()
{memset(DIS,63,sizeof(DIS));cur.dis=0; cur.num=1; cur.tim=0;DIS[1][0]=0;q.push(cur);while(!q.empty()){cur=q.top(); q.pop();if(cur.num==n){printf("%d",cur.dis);return;}if(DIS[cur.num][cur.tim]!=cur.dis) continue;for(int i=front[cur.num];i;i=nxt[i]){if(DIS[to[i]][cur.tim+fly[i]]<cur.dis+val[i]) continue;if(cur.tim+fly[i]>k) continue;DIS[to[i]][cur.tim+fly[i]]=cur.dis+val[i];nt.dis=cur.dis+val[i];nt.tim=cur.tim+fly[i];nt.num=to[i];q.push(nt);}}printf("-1");
}int main()
{freopen("move.in","r",stdin);freopen("move.out","w",stdout);init();dijkstra();return 0;
}

#include<cstdio>
#include<iostream>using namespace std;#define N 5001
#define mod 786433int front[N],to[N<<1],nxt[N<<1],tot;int siz[N],dp[N][N],g[N],cnt[N];int k;void read(int &x)
{x=0; char c=getchar();while(!isdigit(c)) c=getchar();while(isdigit(c)) { x=x*10+c-'0'; c=getchar(); }
}void add(int u,int v)
{to[++tot]=v; nxt[tot]=front[u]; front[u]=tot;to[++tot]=u; nxt[tot]=front[v]; front[v]=tot;
}void init()
{int n;read(n); read(k);int u,v;for(int i=1;i<n;i++){read(u); read(v);add(u,v);}
}void dfs(int x,int y)
{siz[x]=1;dp[x][1]=1;for(int i=front[x];i;i=nxt[i])if(to[i]!=y){dfs(to[i],x);for(int j=1;j<=siz[x]+siz[to[i]];j++) g[j]=0;for(int j=1;j<=siz[x];j++) g[j]=1ll*cnt[to[i]]*dp[x][j]%mod;for(int j=1;j<=siz[x];j++)for(int h=1;h<=siz[to[i]];h++)g[j+h]=(g[j+h]+1ll*dp[x][j]*dp[to[i]][h]%mod)%mod;for(int j=1;j<=siz[x]+siz[to[i]];j++) dp[x][j]=g[j];siz[x]+=siz[to[i]];}for(int i=k;i<=siz[x];i++) cnt[x]+=dp[x][i],cnt[x]%=mod;
}int main()
{freopen("cut.in","r",stdin);freopen("cut.out","w",stdout);init();dfs(1,0);int ans=0;for(int i=k;i<=siz[1];i++) ans+=dp[1][i],ans%=mod;printf("%d",ans);
}

#include<cstdio>
#include<iostream>
#include<algorithm>using namespace std;#define N 5001int n,k;int front[N],to[N<<1],nxt[N<<1],from[N<<1],tot;int ans,cnt;bool use[N];int siz[N];void read(int &x)
{x=0; char c=getchar();while(!isdigit(c)) c=getchar();while(isdigit(c)) { x=x*10+c-'0'; c=getchar(); }
}void add(int u,int v)
{to[++tot]=v; nxt[tot]=front[u]; front[u]=tot; from[tot]=u;to[++tot]=u; nxt[tot]=front[v]; front[v]=tot; from[tot]=v;
}void init()
{read(n); read(k);int u,v;for(int i=1;i<n;i++){read(u); read(v);add(u,v);}
}void dfs2(int x,int y)
{cnt++;for(int i=front[x];i;i=nxt[i])if(to[i]!=y && use[i]) dfs2(to[i],x);
}void judge()
{for(int i=1;i<=n;i++){cnt=0;dfs2(i,0);if(cnt<k) return;}ans++;
}void dfs(int x)
{if(x==(n-1)*2+1) {judge();return;}dfs(x+2);use[x]=use[x+1]=true; dfs(x+2); use[x]=use[x+1]=false;
}int main()
{freopen("cut.in","r",stdin);freopen("cut.out","w",stdout);init();dfs(1);printf("%d",ans);
}