#include <bits/stdc++.h>

using namespace std;

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

int n, m, x, a, b, i, sol;
int v[100005], A[400005];

void build (int nod, int st, int dr){
    if (st == dr){
        A[nod] = v[st];
    }
    else{
        int mid = st + (dr - st)/2;
        build (2*nod, st, mid);
        build (2*nod+1, mid+1, dr);
        A[nod] = max (A[2*nod], A[2*nod+1]);
    }
}

void update (int nod, int st, int dr, int poz, int val){
    if (st == dr){
        A[nod] = val;
    }
    else{
        int mid = st + (dr - st)/2;
        if (poz <= mid){
            update (2*nod, st, mid, poz, val);
        }
        else{
            update (2*nod+1, mid+1, dr, poz, val);
        }
        A[nod] = max (A[2*nod], A[2*nod+1]);
    }
}

void query (int nod, int st, int dr, int a, int b){
    if (a <= st && b >= dr){
        sol = max (sol, A[nod]);
    }
    else{
        int mid = st + (dr - st)/2;
        if (a <= mid){
            query (2*nod, st, mid, a, b);
        }
        if (b > mid){
            query (2*nod+1, mid+1, dr, a, b);
        }
    }
}

int main(){
    fin >> n >> m;
    for (i=1; i<=n; i++){
        fin >> v[i];
    }
    build (1, 1, n);
    for (i=1; i<=m; i++){
        fin >> x >> a >> b;
        if (x == 0){
            sol = -1;
            query (1, 1, n, a, b);
            fout << sol << "\n";
        }
        else{
            update (1, 1, n, a, b);
        }
    }
    return 0;
}
//recapitulare