#include<bits/stdc++.h>
#define lowbit(x) x&(-x)
using namespace std;
const int N=1e5+7;
const int INF=1e9+7;
int m,n,T;
int ans[N],num[N];
struct node
{int x,y,id,op;int k;
} q[N],q1[N],q2[N];
struct Tree
{int tree[N<<2];void add(int x,int val){for (;x<=n;x+=lowbit(x)) tree[x]+=val;}int query(int x){int ans=0;for (;x;x-=lowbit(x)) ans+=tree[x];return ans;}
} G;int cur[N];
void solve(int from,int to,int l,int r)
{if (from>to||l>r) return;if (l==r){for (int i=from;i<=to;i++)if (q[i].op==3) ans[q[i].id]=l;return;}int mid=(l+r)>>1;for (int i=from;i<=to;i++){if (q[i].k<=mid){    if (q[i].op==2) G.add(q[i].x,-1);if (q[i].op==1) G.add(q[i].x,1);}if (q[i].op==3) cur[i]=G.query(q[i].y)-G.query(q[i].x-1);}for (int i=from;i<=to;i++)if (q[i].k<=mid){if (q[i].op==2) G.add(q[i].x,1);if (q[i].op==1) G.add(q[i].x,-1);}int t1=0,t2=0;for (int i=from;i<=to;i++)if (q[i].op==1||q[i].op==2){if (q[i].k<=mid) q1[t1++]=q[i];else q2[t2++]=q[i];}else {if (cur[i]>=q[i].k) q1[t1++]=q[i];else q[i].k-=cur[i],q2[t2++]=q[i];}for (int i=0;i<t1;i++) q[from+i]=q1[i];for (int i=0;i<t2;i++) q[from+t1+i]=q2[i];solve(from,from+t1-1,l,mid);solve(from+t1,to,mid+1,r);
}
int main()
{freopen("dynrank.in","r",stdin);freopen("dynrank.out","w",stdout);scanf("%d",&T);while (T--){scanf("%d%d",&n,&m);for (int i=1;i<=n;i++){int x;scanf("%d",&x);q[i].op=1;q[i].x=i;q[i].k=x;num[i]=x;}int tot=0;for (int i=1;i<=m;i++){char s[5];int x,y,k;scanf("%s",s);scanf("%d%d",&x,&y);if (s[0]=='Q') {scanf("%d",&k);q[++n].op=3;q[n].x=x;q[n].y=y;q[n].id=++tot;q[n].k=k;}if (s[0]=='C'){q[++n].op=2;q[n].x=x;q[n].k=num[x];q[++n].op=1;q[n].x=x;q[n].k=y;num[x]=y;}}solve(1,n,0,INF);for (int i=1;i<=tot;i++) printf("%d\n",ans[i]);}return 0;
}