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

int n,m;
int graf[4*100001+66];
int start,finish,val,pos,left,right,ma;

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

void update(int nod,int left,int right)
{
    if(left==right)
    {
        graf[nod]=val;
        return ;
    }
    int div=(left+right)/2;
    if(pos<=div)update(2*nod, left, div);
    else update(2*nod+1,div+1,right);

    graf[nod]=maxim(graf[2*nod],graf[2*nod+1]);
}

void query(int nod,int left,int right)
{
    if(start<=left&&right<=finish)
    {
        if(graf[nod]>ma)
            ma=graf[nod];
        return ;
    }
    int div=(left+right)/2;
    if(start<=div)
        query(2*nod,left,div);
    if(div<finish)
        query(2*nod+1,div+1,right);
}
int main()
{
    ifstream in("arbint.in");
    ofstream out("arbint.out");
    int x,a,b;
    in>>n>>m;
    for(int i=1;i<=n;i++)
    {
        in>>x;
        pos=i;
        val=x;
        update(1,1,n);
    }
    for(int i=1;i<=m;i++)
    {
        in>>x>>a>>b;
        if(x==0)
        {
            ma=-1;
            start=a;
            finish=b;
            query(1,1,n);
            out<<ma<<"\n";
        }
        else
        {
            pos=a;
            val=b;
            update(1,1,n);
        }
    }
    return 0;
}