#include <bits/stdc++.h>

using namespace std;

vector<int> build_tree(vector<int> v, int n){
    int len = 1 << (int)ceil(log2(n));
    vector<int> seg (2 * len, INT_MIN);

    int k = 1;
    for(int i = len; (i <= 2 * len - 1) && (k <= n); ++i){
        seg[i] = v[k++];
    }
    for(int i = len - 1; i >= 1; --i)
        seg[i] = max(seg[2 * i], seg[2 * i + 1]);

    return seg;
}

void update_tree(vector<int> &seg, int n, int pos, int val){
    int len = 1 << (int)ceil(log2(n));
    pos = len + pos - 1;
    seg[pos] = val;
    for(int k = pos / 2; k >= 1; k /= 2)
        seg[k] = max(seg[2 * k], seg[2 * k + 1]);

}

int querry_tree(vector<int> seg, int n, int l, int r){
    int len = 1 << (int)ceil(log2(n));
    l += len - 1;
    r += len - 1;
    int m = INT_MIN;
    while(l <= r){
        if(l % 2 == 1)
            m = max(m, seg[l++]);
        if(r % 2 == 0)
            m = max(m, seg[r--]);
        l /= 2;
        r /= 2;
    }
    return m;
}

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

#define cin in
#define cout out

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);



    int n, t, i, op;
    vector<int> seg;

    cin >> n >> t;
    vector<int> v(n + 1);

    for(i = 1 ; i <= n; ++i){
        cin >> v[i];
    }

    seg = build_tree(v, n);

    while (t--){
        cin >> op;
        if (op){
            int pos, val;
            cin >> pos >> val;
            update_tree(seg, n, pos, val);
        }
        else{
            int l, r;
            cin >> l >> r;
            cout << querry_tree(seg, n, l, r) << endl;
        }
    }

    return 0;
}