#include <iostream>
#include <fstream>

using namespace std;

/*
    poti folosi in loc de 2*nod pe nod<<1
*/
ifstream r("arbint.in");
ofstream w("arbint.out");
int n, m, x, value, pos, a, b;
int aint[4*100000 + 6];

void update(int nod, int st, int dr){
    if(st == dr){
        aint[nod] = value;
        return;
    }
    int m = (st + dr) / 2;
    if(pos <= m) update(2*nod, st, m);
    else update(2*nod + 1, m+1, dr);

    aint[nod] = max(aint[2*nod], aint[2*nod+1]);
}

void query(int nod, int st, int dr){
    if(a <= st && dr <= b){
        x = max(x, aint[nod]);
        return;
    }
    int m = (st + dr) / 2;
    if(a <= m) query(2*nod, st, m);
    if(b > m) query(2*nod+1, m+1, dr);
}
int main()
{
    r>>n>>m;
    int i;
    for(i=1; i<=n; i++){
       r>>value;
       pos = i;
       update(1, 1, n);
    }

    for(i=1; i<=m; i++){
        r>>value>>a>>b;
        if(value == 0){
            x = -1;
            query(1, 1, n);
            w<<x<<endl;
        }
        else{
            pos = a;
            value = b;
            update(1, 1, n);
        }
    }
    return 0;
}