#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
vector<int>aint;
vector<int>v;
void resizeAint(int n){
    aint.resize(4*n+5);
}
void updateAint(int pozTree,int st,int dr,int pozUpdate,int valUpdate){
    if(st==dr){
        aint[pozTree]=valUpdate;
        return;
    }
    int leftChild=2*pozTree;
    int rightChild=2*pozTree+1;
    int mij=(st+dr)/2;
    if(pozUpdate<=mij){
        updateAint(leftChild, st, mij, pozUpdate,valUpdate);
    }else{
        updateAint(rightChild, mij+1, dr, pozUpdate,valUpdate);
    }
    aint[pozTree]=max(aint[leftChild],aint[rightChild]);
}
void buildAint(int pozTree,int st,int dr){
      if(st==dr){
        aint[pozTree]=v[st-1];
        return;
    }
    int leftChild=2*pozTree;
    int rightChild=2*pozTree+1;
    int mij=(st+dr)/2;
    buildAint(leftChild, st, mij);
    buildAint(rightChild, mij+1, dr);
    aint[pozTree]=max(aint[leftChild],aint[rightChild]);
}
int queryAint(int pozTree,int st,int dr,int stFind,int drFind){
    if(st>=stFind && dr<=drFind){
        return aint[pozTree];
    }
    int leftChild=2*pozTree;
    int rightChild=2*pozTree+1;
    int mij=(st+dr)/2;
    int rightAnswr=0;
    int leftAnswr=0;
    if(stFind<=mij){
        leftAnswr=queryAint(leftChild, st, mij, stFind, drFind);
    }
    if(drFind>mij){
        rightAnswr=queryAint(rightChild, mij+1, dr, stFind, drFind);
    }
    return max(leftAnswr,rightAnswr);
}
int main(){
    int n,q;
    fin>>n>>q;
    resizeAint(n);
    v.resize(n);
    for(int i=0;i<n;++i){
        fin>>v[i];
    }
    buildAint(1, 1, n);
    int op,st,dr,elem,val;
    for(int i=0;i<q;++i){
        fin>>op;
        if(op==0){
            fin>>st>>dr;
           fout<<queryAint(1, 1, n, st, dr)<<"\n";
        }else{
            fin>>elem>>val;
            updateAint(1, 1, n, elem, val);
        }
    }
    return 0;
}