// https://www.infoarena.ro/problema/arbint

#include <fstream>

using namespace std;

#define dim 100001

int N, M, i, X, A, B;
int a[3 * dim];
int start, finish, Val, Pos, maxim;
ifstream fin("arbint.in");
ofstream fout("arbint.out");

void Update(int nod, int l, int r) {
    int m;

    if (l < r) {
        m = (l + r) / 2;
        if (Pos <= m)
            Update(2 * nod, l, m);
        else
            Update(2 * nod + 1, m + 1, r);
        a[nod] = max(a[2 * nod], a[2 * nod + 1]);
    }
    else
        a[nod] = Val;
}

void Query(int nod, int l, int r) {
    int m;

    if (start <= l and r <= finish) { // Maximul intre [l, r] este in a[nod].
        if (maxim < a[nod])
            maxim = a[nod];
    }
    else {
        m = (l + r) / 2;
        if (start <= m)
            Query(2 * nod, l, m);
        if (m < finish)
            Query(2 * nod + 1, m + 1, r);        
    }
}

int main() {
    fin >> N >> M;
    for (i = 1; i <= N; i++) {
        fin >> X;
        Pos = i, Val = X;
        Update(1, 1, N);
    }
    for (i = 1; i <= M; i++) {
        fin >> X >> A >> B;
        if (X == 0) {
            maxim = -1;
            start = A, finish = B;
            Query(1, 1, N);
            fout << maxim << '\n';
        }
        else {
            Pos = A, Val = B;
            Update(1, 1, N);
        }
    }
    return 0;
}

/*
    42 68 35  1 70 25 79 59 63 65  6 46
     1  2  3  4  5  6  7  8  9 10 11 12
          --------------------
    start = 3, finish = 9

Intrare nod = 1, l = 1, r = 12
    m = 6
    3 <= 6 (start <= m)
    Intrare nod = 2, l = 1, r = 6
        m = 3
        3 <= 3 (start <= m)
        Intrare nod = 4, l = 1, r = 3
            m = 2
            2 < 9 (m < finish)
            Intrare nod = 9, l = 3, r = 3
                Maximul intre [3,3] este in a[9] = 35
                maxim = 35
            Iesire nod = 9, l = 3, r = 3
        Iesire nod = 4, l = 1, r = 3
        3 < 9 (m < finish)
        Intrare nod = 5, l = 4, r = 6
            Maximul intre [4,6] este in a[5] = 70
            maxim = 70
        Iesire nod = 5, l = 4, r = 6
    Iesire nod = 2, l = 1, r = 6
    6 < 9 (m < finish)
    Intrare nod = 3, l = 7, r = 12
        m = 9
        3 <= 9 (start <= m)
        Intrare nod = 6, l = 7, r = 9
            Maximul intre [7,9] este in a[6] = 79
            maxim = 79
        Iesire nod = 6, l = 7, r = 9
    Iesire nod = 3, l = 7, r = 12
Iesire nod = 1, l = 1, r = 12
*/