#include <stdio.h>
#include <iostream>

using namespace std;
FILE *in, *out;

int maxim[4*100000+200];
int pos,val,n,m,start,finish,sol;

void update(int node,int left,int right) {
  if(left==right) {
    maxim[node]=val;
    return;
  }
  int mij=(left+right)/2;
  if(pos<=mij)
    update(node*2,left,mij);
  else
    update(node*2+1,mij+1,right);
  maxim[node]=max(maxim[node*2],maxim[node*2+1]);
}

void query(int node, int left, int right){
  if(start<=left && right<=finish){
    if(sol<=maxim[node])
      sol=maxim[node];
    return;
  }
  int mij=(left+right)/2;
  if(start<=mij)
    query(node*2,left,mij);
  if(mij<finish)
    query(node*2+1,mij+1,right);
}

int main() {
    in=fopen("arbint.in","r");
    out=fopen("arbint.out","w");

    fscanf(in,"%d %d",&n,&m);
    for(int i=1;i<=n;i++) {
      int x;
      fscanf(in,"%d",&x);
      pos=i,val=x;
      update(1,1,n);
    }
    for(int i=1;i<=m;i++) {
      int x,a,b;
      sol=-1;;
      fscanf(in,"%d %d %d",&x,&a,&b);
      if(!x){
        start=a,finish=b;
        query(1,1,n);
        fprintf(out,"%d\n",sol);
      }
      else{
        pos=a,val=b;
        update(1,1,n);
      }
    }

    return 0;
}