#include <fstream>

using namespace std;

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

const int N = 1e5 +1;
const int M = 1<<18;
int arb[M];

void actualizare(int p, int st, int dr, int poz, int val){
    if(st==dr){
        arb[p] = val;
        return;
    }
    int m = (st+dr)/2;
    if(poz <= m){
        actualizare(2*p, st, m, poz, val);
    }
    else{
        actualizare(2*p+1, m+1, dr, poz, val);
    }
    arb[p] = max(arb[2*p], arb[2*p+1]);
}

int interogare(int p, int st, int dr, int a, int b){
    if(a<= st && b>=dr){
        return arb[p];
    }
    int m = (st+dr)/2, rezst = -1, rezdr = -1;
    if(a<=m){
        rezst = interogare(2*p,st, m, a, b);
    }
    if(m < b){
        rezdr = interogare(2*p+1,m+1, dr, a, b);
    }
    return max(rezst,rezdr);
}

int main()
{
    int n,m;
    in>>n>>m;
    for(int i=1;i<=n;++i){
        int val;
        in>>val;
        actualizare(1, 1, n, i, val);
    }
    for(int i=0;i<m;++i){
        int tip,a,b;
        in>>tip>>a>>b;
        if(tip){
            actualizare(1, 1, n, a, b);
        }
        else{
            out<<interogare(1, 1, n, a, b)<<'\n';
        }
    }
    return 0;
}