#include <iostream>
#include <fstream>
#define Nmax 300001

using namespace std;

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

int v[Nmax];

int max(int a, int b) {
    if(a > b)
        return a;
    else
        return b;
}

void update(int nod, int st, int dr, int pos, int val) {
    if (st == dr) {
        v[nod] = val;
        return;
    }

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

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

int query(int nod, int lo, int hi, int start, int finish) {
    if (start > hi || lo > finish) {
        return -1;
    }

    if (start <= lo && hi <= finish) {
        return v[nod];
    }

    int mid = (lo + hi) / 2;
    return max(
        query(nod * 2, lo, mid, start, finish),
        query(nod * 2 + 1, mid + 1, hi, start, finish)
    );
}

int main()
{
    int n, m, x, a, b, i, t, maxim;
    in >> n >> m;
    for(i = 1; i <= n; i++) {
        in >> x;
        update(1, 1, n, i, x);
    }
    for(i = 1; i <= m; i++) {
        in >> t >> a >> b;
        if(t == 0) {
            maxim = query(1, 1, n, a, b);
            out << maxim << '\n';
        }
        else {
            update(1, 1, n, a, b);
        }
    }
    in.close();
    out.close();
    return 0;
}