#include <bits/stdc++.h>

using namespace std;

const int nmax = 100010;

inline int Max(int a, int b){
    if (a > b)
        return a;
    return b;
}

int MaxArb[ 4 * nmax ];
int n, m;
int start, stop;
int pos, val;
int maxim;

void update(int nod, int left, int right){
    if (left == right){

        MaxArb[ nod ] = val;
        return;
    }

    int mid = (left + right) / 2;

    if (pos <= mid)
        update(2 * nod, left, mid);
    else
        update(2 * nod + 1, mid + 1, right);

    MaxArb[ nod ] = Max( MaxArb[2 * nod], MaxArb[2 * nod+ 1 ]);
}

void Query(int nod, int left, int right){
    if (start <= left && right <= stop){
        if (maxim < MaxArb[ nod ])
            maxim = MaxArb[ nod ];
            return;
    }

    int mid = (left + right) / 2;
    if ( start <= mid ) Query(2 * nod, left, mid);
    if ( mid < stop ) Query(2 * nod + 1, mid + 1,right);
}


int main(){
    ios_base::sync_with_stdio( false );
    cin.tie( 0 );

    ifstream cin("arbint.in");
    ofstream cout("arbint.out");

    cin >> n >> m;

    for (int i = 0, x; i < n; ++i){
        cin >> x;
        pos = i + 1; val = x;
        update(1, 1, n);
    }

    for (int i = 0, x, y, z; i < m; ++i){
        cin >> x >> y >> z;

        if (x == 0){
            maxim = -1;
            start = y; stop = z;
            Query(1, 1, n);

            cout << maxim << '\n';
        }

        else{
            pos = y; val = z;
            update(1, 1, n);
        }
    }
}