#include <fstream>

using namespace std;

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

int n, m;
int tree[262160], v[100000];
int maxim = -1; // pentru query

void update(int node, int left, int right, int pos, int x) {
    if (left == right) {
        tree[node] = x;
        return;
    }

    int mid = (left + right) / 2;
    if (pos <= mid)
        update(2 * node, left, mid, pos, x);
    else
        update(2 * node + 1, mid + 1, right, pos, x);

    tree[node] = max(tree[2 * node], tree[2 * node + 1]);

}

void query(int node, int left, int right, int a, int b) {
    if (a <= left && b >= right){
        maxim = max(maxim, tree[node]);
        return;
    }

    int mid = (left + right) / 2;
    if (a <= mid)
        query(2 * node, left, mid, a, b);
    if (b > mid)
        query(2 * node + 1, mid + 1, right, a, b);
}

int main(){
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        cin >> v[i];
        update(1, 1, n, i, v[i]);
    }

    for (int i = 1; i <= m; i++) {
        int option, a, b;
        cin >> option >> a >> b;

        if (option == 1)
            update(1, 1, n, a, b);
        else {
            maxim = -1;
            query(1, 1, n, a, b);
            cout << maxim << '\n';
        }

    }

//    for (int i = 1; i <= 2 * n - 1; i++)
//        cout << tree[i] << ' ';

    return 0;
}