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

int N, M;
int ai[400400] , maxim;

void Update(int nod, int left, int right , int Pos , int Val)
{
    if (left == right)
    {
        ai[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);

    ai[nod] = max(ai[2*nod], ai[2*nod+1]);
}
void Query(int nod, int left, int right , int start , int finish)
{
    if (start <= left && finish >= right)
    {
        if (maxim < ai[nod]) maxim = ai[nod];
        return;
    }
    int mid = (left+right)/2;
    if (start <= mid)
        Query(2*nod , left , mid , start , finish);
    if (mid < finish)
        Query(2*nod+1 , mid+1 , right , start , finish);
}

int main()
{
    int X, A, B;
    ifstream fin("arbint.in"); ofstream fout("arbint.out");
    fin>>N>>M;
    for (int i = 1; i <= N; i++)
    {
        fin>>X;
        Update(1,1,N,i,X);
    }

    for (int i = 1; i <= M; i++)
    {
        fin>>X>>A>>B;
        if (X == 0)
        {
            maxim = -1;
            Query(1,1,N,A,B);
            fout << maxim << "\n";
        }
        if (X == 1)
            Update(1,1,N,A,B);
    }
}