#include <bits/stdc++.h>

using namespace std;


// tutorial bun care explica segment trees (au legatura): https://www.youtube.com/watch?v=ZBHKZF5w4YU

int arbore[400'100];
int n, m, start, finish, val, pos, maxim, x, a, b;

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

void quer(int nod, int stanga, int dreapta)
{
    if(start <= stanga && dreapta <= finish){
        if(maxim < arbore[nod])
            maxim = arbore[nod];
        return;
    }

    int mij = (stanga + dreapta) / 2;
    if(start <= mij){
        quer(2 * nod, stanga, mij);
    }
    if(mij < finish){
        quer(2 * nod + 1, mij + 1, dreapta);
    }
}

void update(int nod, int stanga, int dreapta)
{
    if(stanga == dreapta){
        arbore[nod] = val;
        return;
    }
    int mij = (stanga + dreapta) / 2;
    if(pos <= mij){
        update(2 * nod, stanga, mij);
    }
    else{
        update(2 * nod + 1, mij + 1, dreapta);
    }

    arbore[nod] = maxxim(arbore[2 * nod], arbore[2 * nod + 1]);
}


int main()
{


    ifstream f("arbint.in");
    ofstream o("arbint.out");

    f >> n >> m;

    for(int i = 1; i <= n; i++){
        f >> x;
        pos = i;
        val = x;
        // cout << x << endl;
        update(1, 1, n);
    }

    for(int i = 1; i <= m; i++){
        f >> x >> a >> b;
        if(x == 0){
            maxim = -1;
            start = a, finish = b;
            quer(1, 1, n);

            o << maxim << '\n';
        }
        else{
            pos = a, val = b;
            update(1, 1, n);
        }
    }

    return 0;
}