#include <fstream>


using namespace std;

int n, i, v[100001], a[400001], sol, x, y, t, m;

ifstream fin("arbint.in");
ofstream fout("arbint.out");

void build(int nod, int st, int dr){
    if(st == dr){
        a[nod] = v[st];
        return;
    }
    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 st, int dr){
    if(st == dr){
        a[nod] = y;
        return;
    }
    int mid = (st+dr)/2;
    if(x <= mid)
        update(2*nod, st, mid);
    if(x > mid)
        update(2*nod+1, mid+1, dr);
    a[nod] = max(a[2*nod], a[2*nod+1]);
}

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

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>>x>>y;
        if(t == 0){
            sol = -1;
            query(1, 1, n);
            fout<<sol<<"\n";
        }
        else
            update(1, 1, n);
    }
    return 0;
}