#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

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

int v[300005],n,m,mx;

void arb_update(int nod,int left,int right,int pos,int val)
{
    if (left==right)
        v[nod]=val;
    else
    {
        int mid=(left+right)/2;
        if (pos<=mid)
            arb_update(nod*2,left,mid,pos,val);
        else
            arb_update(nod*2+1,mid+1,right,pos,val);
        v[nod]=max(v[nod*2],v[nod*2+1]);
    }
}

void arb_query(int nod,int st,int dr,int left,int right)
{
    if(left<=st and dr<=right) mx=max(mx,v[nod]);
    else
    {
        int mid=(st+dr)/2;
        if(left<=mid) arb_query(nod*2,st,mid,left,right);
        if(mid<right) arb_query(nod*2+1,mid+1,dr,left,right);
    }
}

void read()
{
    int x,tip,a,b;
    f>>n>>m;
    for (int i=1; i<=n; ++i)
    {
        f>>x;
        arb_update(1,1,n,i,x);
    }
    for (int i=0; i<m; ++i)
    {
        f>>tip>>a>>b;
        if (tip==0)
        {
            mx=0;
            arb_query(1,1,n,a,b);
            t<<mx<<'\n';
        }
        else arb_update(1,1,n,a,b);
    }
}

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