#include <iostream>
#include <fstream>
using namespace std;

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

const int nmax = 1e5 + 5;
int Aint[nmax << 2], maxx;

void Update (int node, int st, int dr, int pos, int val) {
    if (st == dr) {
        Aint[node] = val;
        return;
    }
    int mid = (st + dr) >> 1;
    if (pos <= mid) {
        Update(node << 1, st, mid, pos, val);
    } else {
        Update(node << 1 | 1, mid + 1, dr, pos, val);
    }
    Aint[node] = max(Aint[node << 1], Aint[node << 1 | 1]);
}

void Query (int node, int st, int dr, int inc, int sf) {
    if (inc <= st && dr <= sf) {
        maxx = max(maxx, Aint[node]);
        return;
    }
    int mid = (st + dr) >> 1;
    if (inc <= mid) {
        Query(node << 1, st, mid, inc, sf);
    }
    if (sf > mid) {
        Query(node << 1 | 1, mid + 1, dr, inc, sf);
    }
}

int main() {
    ios_base :: sync_with_stdio (false);
    int n, m, x, y, a, i;
    fin >> n >> m;
    for (i = 1; i <= n; i++) {
        fin >> x;
        Update(1, 1, n, i, x);
    }
    for (i = 1; i <= m; i++) {
        fin >> a >> x >> y;
        if (a == 0) {
            maxx = -1;
            Query(1, 1, n, x, y);
            fout << maxx << "\n";
        } else {
            Update(1, 1, n, x, y);
        }
    }
    fin.close();
    fout.close();
    return 0;
}