#include<bits/stdc++.h>

 using namespace std;

 #define Fopen freopen("_in.txt","r",stdin); freopen("_out.txt","w",stdout);

 #define LL long long

 #define ULL unsigned LL

 #define fi first

 #define se second

 #define pb push_back

 //#define lson l,m,rt<<1

 //#define rson m+1,r,rt<<1|1

 #define max3(a,b,c) max(a,max(b,c))

 #define min3(a,b,c) min(a,min(b,c))

 typedef pair<int,int> pll;

 const int INF = 0x3f3f3f3f;

 const LL mod =  (int)1e9+;

 const int N = ;

 const int M = ;

 int root[N], S[N], lson[M], rson[M], ll[N], rr[N], cnt[M];

 int tot, t;

 int lsz, rsz;

 int a[N], b[N];

 struct Node{

     int l, r, op, k;

 }A[N];

 int Build(int l, int r){

     int now = ++tot;

     cnt[now] = ;

     if(l < r){

         int m = l+r >> ;

         lson[now] = Build(l,m);

         rson[now] = Build(m+,r);

     }

     return now;

 }

 int Update(int l, int r, int pre, int pos, int v){

     int now = ++tot;

     cnt[now] = cnt[pre] + v;

     if(l < r){

         int m = l+r >> ;

         if(pos <= m){

             rson[now] = rson[pre];

             lson[now] = Update(l, m, lson[pre], pos, v);

         }

         else {

             lson[now] = lson[pre];

             rson[now] = Update(m+, r, rson[pre], pos, v);

         }

         cnt[now] = cnt[lson[now]] + cnt[rson[now]];

     }

     return now;

 }

 int Query(int l, int r, int L, int R, int k){

     if(l == r) return l;

     int num1 = cnt[lson[L]];

     int num2 = cnt[lson[R]];

     for(int i = ; i <= lsz; i++) num1 += cnt[lson[ll[i]]];

     for(int i = ; i <= rsz; i++) num2 += cnt[lson[rr[i]]];

     num2 -= num1;

     int m = l+r >> ;

     if(num2 >= k){

         for(int i = ; i <= lsz; i++) ll[i] = lson[ll[i]];

         for(int i = ; i <= rsz; i++) rr[i] = lson[rr[i]];

         return Query(l, m, lson[L], lson[R], k);

     }

     else {

         for(int i = ; i <= lsz; i++) ll[i] = rson[ll[i]];

         for(int i = ; i <= rsz; i++) rr[i] = rson[rr[i]];

         return Query(m+, r, rson[L], rson[R], k-num2);

     }

 }

 int id(int x){

     return lower_bound(b+, b++t, x) - b;

 }

 int lowbit(int x){

     return x&(-x);

 }

 int main(){

     int T;

     scanf("%d", &T);

     while(T--){

         tot = t = ;

         int n, m;

         char s[];

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

         for(int i = ; i <= n; i++) scanf("%d", &a[i]), b[++t] = a[i];

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

             scanf("%s", s);

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

                 A[i].op = ;

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

             }

             else {

                 A[i].op = ;

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

                 b[++t] = A[i].r;

             }

         }

         sort(b+, b++t);

         int tmp = ;

         for(int i = ; i <= t; i++)

             if(b[i] != b[i-]) b[++tmp] = b[i];

         t = tmp;

         root[] = Build(, t);

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

             root[i] = Update(, t, root[i-], id(a[i]), );

         }

         for(int i = ; i <= n; i++) S[i] = root[];

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

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

                 lsz = rsz = ;

                 for(int j = A[i].l-; j; j-=lowbit(j)) ll[++lsz] = S[j];

                 for(int j = A[i].r; j; j-=lowbit(j)) rr[++rsz] = S[j];

                 printf("%d\n", b[Query(,t,root[A[i].l-], root[A[i].r], A[i].k)]);

             }

             else {

                 for(int j = A[i].l; j <= t; j += lowbit(j)) S[j] = Update(, t, S[j], id(a[A[i].l]), -);

                 for(int j = A[i].l; j <= t; j += lowbit(j)) S[j] = Update(, t, S[j], id(A[i].r), );

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

             }

         }

     }

     return ;

 }