#include<cstdio>

 #include<cstring>

 #include<cstdlib>

 #include<iostream>

 #include<algorithm>

 #include<vector>

 #include<cmath>

 #define ls(i) T[i].ls

 #define rs(i) T[i].rs

 #define w(i) T[i].w

 #define Find(i) (lower_bound(LX.begin(),LX.begin()+n1,i)-LX.begin())+1

 using namespace std;

 const int N=+;

 struct node{

     int ls,rs,w;

     node(){ls=rs=w=;}

 }T[];

 struct ope{

     int i,l,r,k;

 }op[];

 vector<int> LX,Q1,Q2;

 int n,n1,m,cnt;

 int a[],root[*];

 inline int lowbit(int x){

     return x&-x;

 }

 void build(int &i,int l,int r,int x){

     T[++cnt]=T[i]; i=cnt;

     w(i)++;

     if (l==r) return;

     int m=(l+r)>>;

     if (x<=m) build(ls(i),l,m,x);

     else build(rs(i),m+,r,x);

 }

 void ins(int &i,int l,int r,int x,int v){

     if (i==){ T[++cnt]=T[i]; i=cnt; }

     w(i)+=v;

     if (l==r) return;

     int m=(l+r)>>;

     if (x<=m) ins(ls(i),l,m,x,v);

     else ins(rs(i),m+,r,x,v);

 }

 void my_ins(int pos,int x,int v){

     int t=Find(x);

     for (int i=pos;i<=n;i+=lowbit(i)){

         ins(root[i],,n1,t,v);

     }

 }

 int Qy(vector<int> Q1,vector<int> Q2,int l,int r,int k){

     if (l==r) return l;

     int c=;

     int m=(l+r)>>;

     for (int i=;i<Q1.size();i++) c-=w(ls(Q1[i]));

     for (int i=;i<Q2.size();i++) c+=w(ls(Q2[i]));

     for (int i=;i<Q1.size();i++) Q1[i]=(c>=k?ls(Q1[i]):rs(Q1[i]));

     for (int i=;i<Q2.size();i++) Q2[i]=(c>=k?ls(Q2[i]):rs(Q2[i]));

     if (c>=k) return Qy(Q1,Q2,l,m,k);

     else return Qy(Q1,Q2,m+,r,k-c);

 }

 void query(int l,int r,int k){

     Q1.clear();Q2.clear();

     Q1.push_back(root[l!=?l-+n:]);

     Q2.push_back(root[r+n]);

     for (int i=l-;i>;i-=lowbit(i)) Q1.push_back(root[i]);

     for (int i=r;i>;i-=lowbit(i)) Q2.push_back(root[i]);

     int t=Qy(Q1,Q2,,n1,k);

     printf("%d\n",LX[t-]);

 }

 void work(){

     cnt=;

     //for (int i=0;i<n1;i++) cout<<list[i]<<" ";cout<<endl;

     memset(root,,sizeof(root));

     for (int i=;i<=n;i++){

         root[i+n]=root[i-+n];

         int t=Find(a[i]);

         build(root[i+n],,n1,t);

     }

     for (int i=;i<m;i++){

         if (op[i].i==){

             query(op[i].l,op[i].r,op[i].k);

         //    cout<<"*** "<<i<<endl;

         }else{

             my_ins(op[i].l,a[op[i].l],-);

             my_ins(op[i].l,op[i].r,);

             a[op[i].l]=op[i].r;

         }

     }

 }

 int main(){

     int Cas;scanf("%d",&Cas);

     while (Cas--){

         scanf("%d%d",&n,&m);

         LX.clear();

         for (int i=;i<=n;i++){

             scanf("%d",&a[i]);LX.push_back(a[i]);

         }

         char s[];

         for (int i=;i<m;i++){

             scanf("%s",s);

             if (s[]=='Q'){

                 op[i].i=;

                 scanf("%d%d%d",&op[i].l,&op[i].r,&op[i].k);

             }else{

                 op[i].i=;

                 scanf("%d%d",&op[i].l,&op[i].r);

                 LX.push_back(op[i].r);

             }

         }

         sort(LX.begin(),LX.end());

         n1=unique(LX.begin(),LX.end())-LX.begin();

         work();

     }

     return ;

 }