#include <fstream>
#include <algorithm>
#define MaxN 100005
using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");

int N, M, arb[4*MaxN+100], tip, x, y, pos, val, maxim, start, finish;

void update(int nod, int left, int right)
{
    if (left==right)
    {
        arb[nod]=val; return;
    }

    int mij=(left+right)/2;

    if (pos<=mij) update(2*nod, left, mij);
         else update(2*nod+1, mij+1, right);

    arb[nod]=max(arb[2*nod], arb[2*nod+1]);
}

void query(int nod, int left, int right)
{
    if (start<=left && right<=finish)
    {
        if (maxim<arb[nod])
            maxim=arb[nod];
        return;
    }

    int mij=(left+right)/2;

    if (x<=mij) query(2*nod, left, mij);
    if (mij<finish) query(2*nod+1, mij+1, right);
}

int main()
{
    f>>N>>M;
    for (int i=1; i<=N; ++i)
    {
        f>>val; pos=i;
        update(1, 1, N);
    }

    for (int i=1; i<=M; ++i)
    {
        f>>tip>>x>>y;
        if (tip)
        {
            pos=x; val=y;
            update(1, 1, N);
        }
        else
        {
            maxim=-1;
            start=x; finish=y;
            query(1, 1, N, x, y);
            g<<maxim<<'\n';
        }
    }
}