#include <iostream>
#include <fstream>
#define DIM 100001
using namespace std;
ifstream fin ("arbint.in");
ofstream fout ("arbint.out");

int n, m;
int ST[4 * DIM + 66];
int maxim;

void update (int node, int pos, int val, int st, int dr) {
    if (st == dr) ST[node] = val;
    else {
        int mid = (st + dr) / 2;
        if (pos <= mid) update(2 * node, pos, val, st, mid);
        else update(2 * node + 1, pos, val, mid + 1, dr);
        ST[node] = max(ST[2 * node], ST[2 * node + 1]);
    }
}

void query (int node, int left, int right, int x, int y) {
    if (left >= x && right <= y) {
        if (maxim < ST[node]) maxim = ST[node];
    }
    else {
        int mid = (left + right) / 2;
        if (mid >= x)
            query(2 * node, left, mid, x, y);
        if (mid < y)
            query(2 * node + 1, mid + 1, right, x, y);
    }
}

int main() {
    int i;
    int x, a, b;

    fin >> n >> m;

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

    for (i = 1; i <= m; ++i) {
        fin >> x >> a >> b;
        if (x == 0) {
            maxim = -1;
            query(1, 1, n, a, b);

            fout << maxim << '\n';
        }
        else {
            update(1, a, b, 1, n);
        }
    }

    return 0;
}