#include <fstream>
#include <iostream>
using namespace std;

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

int n, m, arbint[400005], a, b, t, res;

void update(int nod, int st, int dr, int pos, int val) {
    if(st == dr) {
        arbint[nod] = val;
        return;
    }
    int m = (st+dr)/2;
    if(pos <= m)
        update(2*nod, st, m, pos, val);
    else
        update(2*nod+1, m+1, dr, pos, val);
    arbint[nod] = max(arbint[2*nod], arbint[2*nod+1]);
}

void query(int nod, int st, int dr) {
    if(a <= st && dr <= b) {
        res = max(res, arbint[nod]);
        return;
    }
    int m = (st+dr)/2;
    if(a <= m)
        query(2*nod, st, m);
    if(m < b)
        query(2*nod+1, m+1, dr);
}


void citire() {
    fin >> n >> m;
    int x;
    for(int i = 1; i <= n; i++) {
        fin >> x;
        update(1, 1, n, i, x);
    }
}

int main() {
    citire();
    while(m--) {
        fin >> t >> a >> b;
        if(t == 0) {
            res = 0;
            query(1, 1, n);
            fout << res << '\n';
        } else update(1, 1, n, a, b);
    }
}