#include <bits/stdc++.h>

#define DIM 100000

#define int long long

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

//ifstream f("filesmodel.in");
//ofstream g("filesmodel.out");

int n,m;
int c,a,b;
int aint[4*DIM+5];
int sol;

void build(int nod,int st,int dr){

    if(st == dr){
        f>>aint[nod];
        return;
    }

    int mid = (st+dr)/2;

    build(2*nod,st,mid);
    build(2*nod+1,mid+1,dr);

    aint[nod] = max(aint[2*nod],aint[2*nod+1]);
}

void query(int nod,int st,int dr,int a,int b){

    if(a<=st && dr<=b){
        sol = max(sol,aint[nod]);
        return;
    }

    int mid = (st+dr)/2;

    if(a<=mid){
        query(2*nod,st,mid,a,b);
    }
    if(mid+1<=b){
        query(2*nod+1,mid+1,dr,a,b);
    }

    ///aint[nod] = max(aint[2*nod],aint[2*nod+1]);
}

void update(int nod,int st,int dr,int poz,int val){

    if(st == dr){
        aint[nod] = val;
        return;
    }

    int mid = (st+dr)/2;

    if(poz<=mid){
        update(2*nod,st,mid,poz,val);
    }else{
        update(2*nod+1,mid+1,dr,poz,val);
    }

    aint[nod] = max(aint[2*nod],aint[2*nod+1]);
}

signed main(){

    f>>n>>m;
    build(1,1,n);

    while(m--){
        f>>c>>a>>b;
        if(c == 0){
            sol = -1;
            query(1,1,n,a,b);
            g<<sol<<'\n';
        }else{
            update(1,1,n,a,b);
        }
    }
    return 0;
}