#include <fstream>
using namespace std;
ifstream in ("arbint.in");
ofstream out ("arbint.out");
const int Nmax=400005;
int n,m,A[Nmax],maxim;
void Query (int nod,int left, int right, int start, int finish)
{
    if (left>=start&&right<=finish)
    {
        maxim=max(maxim,A[nod]);
        return;
    }
    int mid=(left+right)/2;
    if(mid>=start)
    {
        Query(2*nod,left,mid,start,finish);
    }
    if (mid<finish)
    {
        Query(2*nod+1,mid+1,right,start,finish);
    }
}
void Update(int nod,int left,int right, int pos, int val)
{
    if (left==right)
    {
        A[nod]=val;
        return;
    }
    int mid=(left+right)/2;
    if (pos<=mid)
    {
        Update(2*nod,left,mid,pos,val);
    }
    else
    {
        Update(2*nod+1,mid+1,right,pos,val);
    }
    A[nod]=max(A[2*nod],A[2*nod+1]);
}
void RSP()
{
    int x,y,opt;
    in>>n>>m;
    for(int i=1;i<=n;i++)
    {
        in>>x;
        Update(1,1,n,i,x);
    }
    for (int i=1;i<=m;i++)
    {
        in>>opt>>x>>y;
        if (opt==1)
        {
            Update(1,1,n,x,y);
        }
        else
        {
            maxim=-1;
            Query(1,1,n,x,y);
            out<<maxim<<'\n';
        }
    }
}
int main()
{
    RSP();
    return 0;
}