#include <cstdio>

 #include <iostream>

 #include <algorithm>

 #include <cstring>

 #include <cmath>

 #define REP(i, s, n) for(int i = s; i <= n; i ++)

 #define RAP(i, n, s) for(int i = n; i >= s; i --)

 #define LOW for(; x; x -= x & (-x))

 using namespace std;

 const int maxn =  + ;

 const int Maxn = ;

 const int maxnode =  * maxn;

 int s[maxnode], ls[maxnode], rs[maxnode], A[maxn], root[maxn], Ln, Rn, L[maxn], R[maxn], c[maxn];

 int n, Q, ms = ;

 void update(int x, int& y, int L, int R, int pos, int v){

     s[y = ++ ms] = s[x] + v;

     if(L == R) return ;

     int M = L + R >> ;

     ls[y] = ls[x]; rs[y] = rs[x];

     if(pos <= M) update(ls[x], ls[y], L, M, pos, v);

     else update(rs[x], rs[y], M + , R, pos, v);

     return ;

 }

 void update(int x, int v){

     for(int i = x; i <= Maxn; i += i & (-i)) update(c[i], c[i], , Maxn, A[x], -); A[x] = v;

     for(int i = x; i <= Maxn; i += i & (-i)) update(c[i], c[i], , Maxn, A[x], ); return ;

 }

 void init(int x, int tp){

     if(!tp) { L[++ Ln] = root[x]; LOW if(c[x]) L[++ Ln] = c[x]; }

     else { R[++ Rn] = root[x]; LOW if(c[x]) R[++ Rn] = c[x]; }

     return ;

 }

 int query(int ql, int qr, int k){

     Ln = Rn = ; init(qr, ); init(ql - , );//0是左

     int ll = , rr = Maxn;

     while(ll < rr){

         int Lsum = , Rsum = , M = ll + rr >> ;

         REP(i, , Ln) Lsum += s[ls[L[i]]];

         REP(i, , Rn) Rsum += s[ls[R[i]]];

         int kth = Rsum - Lsum;

         if(kth >= k){//往左找

             REP(i, , Ln) L[i] = ls[L[i]];

             REP(i, , Rn) R[i] = ls[R[i]];

             rr = M;

         }

         else{//往右找

             REP(i, , Ln) L[i] = rs[L[i]];

             REP(i, , Rn) R[i] = rs[R[i]];

             ll = M + ; k -= kth; //看好了二分！ 别忘了还要减 Σ( ° △ °|||)︴

         }

     }

     return ll;

 }

 inline void read(int &x){

     x = ; int sig = ; char ch = getchar();

     while(!isdigit(ch)) { if(ch == '-') sig = -; ch = getchar(); }

     while(isdigit(ch)) x =  * x + ch - '', ch = getchar();

     x *= sig; return ;

 }

 inline void write(int x){

     if(x == ) { putchar(''); return ; }

     if(x < ) putchar('-'), x = -x;

     int len = , buf[];

     while(x) buf[len ++] = x % , x /= ;

     RAP(i, len - , ) putchar(buf[i] + ''); return ;

 }

 void init(){

     read(n); read(Q);

     REP(i, , n) read(A[i]);

     REP(i, , n) update(root[i - ], root[i], , Maxn, A[i], );

     return ;

 }

 void work(){

     int tp, ql, qr, k, x, v;

     while(Q --){

         read(tp);

         if(tp) read(ql), read(qr), read(k), write(query(ql, qr, k) - ), putchar('\n');// 减一

         else read(x), read(v), update(x, v);

     }

     return ;

 }

 void print(){

     return ;

 }

 int main(){

     init();

     work();

     print();

     return ;

 }

 #include<iostream>

 #include<cstdio>

 #include<cmath>

 #include<algorithm>

 #define t node[d]

 #define cnt countn[d]

 #define repnode(d) for(int i=1;i<=countn[d];i++)

 using namespace std;

 const int maxn=+,maxnode=+,Max=;

 int ls[maxnode],rs[maxnode],s[maxnode],root[maxn],A[maxn],c[maxn],n,m,ms=,countn[],node[][maxn],sum[];

 void update(int x,int& y,int L,int R,int pos,int d){

     s[y=++ms]=s[x]+d;

     if(L==R) return;

     ls[y]=ls[x];rs[y]=rs[x];

     int M=L+R>>;

     if(pos<=M) update(ls[x],ls[y],L,M,pos,d);

     else update(rs[x],rs[y],M+,R,pos,d);

     return;

 }

 void update(int x,int v){

     for(int i=x;i<=Max;i+=i&-i) update(c[i],c[i],,Max,A[x],-);A[x]=v;

     for(int i=x;i<=Max;i+=i&-i) update(c[i],c[i],,Max,A[x],);return;

 }

 void init(int x,int d){

     t[++cnt]=root[x];

     for(;x;x-=x&-x) if(c[x]) t[++cnt]=c[x];

     return;

 }

 int query(int ql,int qr,int k){

     countn[]=countn[]=;

     init(qr,);init(ql-,);

     int L=,R=Max,d;

     while(L<R){

         sum[]=sum[]=;

         int M=L+R>>;

         repnode(d=) sum[d]+=s[ls[t[i]]];

         repnode(d=) sum[d]+=s[ls[t[i]]];

         int kth=sum[]-sum[];

         if(k<=kth){

             repnode(d=) t[i]=ls[t[i]];

             repnode(d=) t[i]=ls[t[i]];

             R=M;

         }

         else{

             repnode(d=) t[i]=rs[t[i]];

             repnode(d=) t[i]=rs[t[i]];

             L=M+;k-=kth;

         }

     } return L;

 }

 inline int read(){

     int x=,sig=;char ch=getchar();

     while(!isdigit(ch)){if(ch=='-') sig=-;ch=getchar();}

     while(isdigit(ch)) x=*x+ch-'',ch=getchar();

     return x*=sig;

 }

 inline void write(int x){

     if(x==){putchar('');return;} if(x<) putchar('-'),x=-x;

     int len=,buf[]; while(x) buf[len++]=x%,x/=;

     for(int i=len-;i>=;i--) putchar(buf[i]+'');return;

 }

 void init(){

     n=read();m=read();

     for(int i=;i<=n;i++) A[i]=read();

     for(int i=;i<=n;i++) update(root[i-],root[i],,Max,A[i],);

     return;

 }

 void work(){

     int tp,i,j,k,x,v;

     while(m--){

         tp=read();

         if(tp){

             i=read();j=read();k=read();

             write(query(i,j,k)-);putchar('\n');

         }

         else{

             x=read();v=read();

             update(x,v);

         }

     }

     return;

 }

 void print(){

     return;

 }

 int main(){

     init();work();print();return ;

 }