#include <bits/stdc++.h>

using namespace std;

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

int t[400100];
int n;

void build () {
    for (int i = n-1; i > 0; i--) t[i] = max(t[i<<1], t[i<<1|1]);
}

void update (int p, int value) {
    for (t[p += n] = value; p > 1; p >>= 1) t[p>>1] = max(t[p], t[p^1]);
}

int query (int l, int r)
{
    int res = 0;
    for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
        if (l&1) res = max(res, t[l++]);
        if (r&1) res = max(res, t[--r]);
    }
    return res;
}

int main() 
{
    int q;
    cin >> n >> q;
    for (int i = 0; i < n; i++) {
        cin >> t[n+i];
    }
    build();
    for (int i = 0; i < q; i++) {
        int type, ind, val, l, r;
        cin >> type;
        if (type == 1) {
            cin >> ind >> val;
            ind--;
            update(ind, val);
        } else {
            cin >> l >> r;
            l--;
            cout << query(l, r) << "\n";
        }
    }
}