#include <bits/stdc++.h>

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n, m, x, Max[400005];
int pos, val, start, finish, maxim;
void update(int nod, int left, int right)
{
    if(left==right)
    {
        Max[nod]=val;
        return;
    }
    int mij=(left+right)/2;
    if(pos<=mij)update(nod*2, left, mij);
    else update(nod*2+1, mij+1, right);
    Max[nod]=max(Max[nod*2], Max[nod*2+1]);
}
void query(int nod, int left, int right)
{
    if(start<=left && right<=finish)
    {
        if(maxim<Max[nod])maxim=Max[nod];
        return;
    }
    int mij=(left+right)/2;
    if(start<=mij)query(nod*2,left,mij);
    if(mij<finish)query(nod*2+1,mij+1,right);
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=n;++i)
    {
        fin>>x;
        pos=i; val=x;
        update(1,1,n);
    }
    for(int i=1;i<=m;++i)
    {int caz,a,b;
        fin>>caz>>a>>b;
        if(caz){pos=a;val=b;update(1,1,n);}
        else
        {
            maxim=-1;
            start=a;finish=b;
            query(1,1,n);
            fout<<maxim<<'\n';
        }
    }
    //cout << "Hello world!" << endl;
    return 0;
}