#include <fstream>
#define dim 100001
using namespace std;
int n, m, i, j, sol, v[dim], t, a, b;
int A[4*dim + 66];
ifstream fin("arbint.in");
ofstream fout("arbint.out");

void build (int nod, int st, int dr)
{
    if (st == dr) {
        A[nod] = v[dr];
    } else {
        int mid = (st + dr) / 2;
        build(2 * nod, st, mid);
        build(2 * nod + 1, mid + 1, dr);
        A[nod] = max(A[2 * nod], A[2 * nod + 1]);
    }
}

void update (int nod, int p, int st, int dr, int x)
{
    if (st == dr) {
        A[nod] = x;
    } else {
        int mid = (st + dr) / 2;
        if (p <= mid) {
            update(2 * nod, p, st, mid, x);
        } else {
            update(2 * nod + 1, p, mid + 1, dr, x);
        }
        A[nod] = max(A[2 * nod], A[2 * nod + 1]);
    }
}

void query (int nod, int st, int dr, int a, int b, int &sol) {
    if (a <= st && dr <= b) {
        sol = max(sol, A[nod]);
    } else {
        int mid = (st + dr) / 2;
        if (a <= mid) {
            query(2 * nod, st, mid, a, b, sol);
        }
        if (b > mid) {
            query(2 * nod + 1, mid + 1, dr, a, b, sol);
        }
    }
}

int main() {
    fin >> n >> m;
    for (i = 1; i <= n; i++) {
        fin >> v[i];
    }
    build(1, 1, n);
    for (i = 1; i <= m; i++) {
        fin >> t >> a >> b;
        if (t == 0) {
            sol = -1;
            query(1, 1, n, a, b, sol);
            fout << sol << "\n";
        } else {
            update(1, a, 1, n, b);
        }
    }

    return 0;
}