#include <iostream>
#include <fstream>
using namespace std;

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

const int NMAX = 100009;

const int INF = 1<<31-1;

int v[NMAX];
int tree[4*NMAX];

int n,m;

void Update(int nod, int lf, int rg, int pos, int val)
{
    if(lf == rg)
    {
        tree[nod] = val;
        return;
    }
    int mid = lf + (rg-lf)/2;
    if(pos <= mid)
        Update(nod*2, lf, mid, pos, val);
    else Update(nod*2+1, mid+1, rg, pos, val);
    tree[nod] = max( tree[nod*2], tree[nod*2+1] );
}

int Query(int nod, int lf, int rg, int L, int R)
{
    if(L<=lf && rg<= R)
    {
        return tree[nod];
    }
    int mid = lf + (rg-lf)/2;
    int maxx = -2;
    if(L <= mid)
        maxx = max( maxx, Query(nod*2, lf, mid, L, R) );
    if(mid < R)    maxx = max(maxx,Query(nod*2+1, mid+1, rg, L, R) );
    return maxx;

}

void Read()
{
    int i,j,a,b,x;
    fin>>n>>m;
    for(i=1; i<=n; ++i)
    {
        fin>>x;
        Update(1,1,n,i,x);
    }
    for(i=1; i<=n; ++i)
    {
        fin>>x>>a>>b;
        if( x == 0 )
        {
            fout<<Query(1,1,n,a,b)<<"\n";
        }
        else Update(1,1,n,a,b);
    }

}

int main()
{
    Read();
    return 0;
}