#include <iostream>
#include <fstream>

using namespace std;
ifstream fin ("arbint.in");
ofstream fout ("arbint.out");
int i,j,a,x,y,pos,val,finish,start,Max,n,m,arb[400001];

void update ( int nod, int st, int dr)
{
    if (st==dr)
    {
        arb[nod]=val;
        return;
    }
    int mid=(st+dr)/2;
    if (pos<=mid)
        update (nod*2,st,mid);
    else
        update (nod*2+1,mid+1,dr);
    arb[nod]=max(arb[nod*2],arb[nod*2+1]);
}

void query ( int nod, int st, int dr)
{
    if (st >= start&& dr <= finish)
    {
        Max=max(Max,arb[nod]);
        return;
    }
    int mid=(st+dr)/2;
    if ( start<=mid)
        query(nod*2,st,mid);
    if (mid < finish)
        query(nod*2+1,mid+1,dr);
}
int main()
{
    fin >> n >> m;
    for (i=1;i<=n;i++)
    {
        fin>> val;
        pos=i;
        update(1,1,n);
    }

    for (i=1;i<=m;i++)
    {
        fin>>a>>x>>y;
        if(a==1)
        {
            pos=x;val=y;
            update(1,1,n);
        }
        else
        {
            Max=-1;
            start=x;finish=y;
            query(1,1,n);
            fout<< Max << "\n";
        }
    }
    return 0;
}