#include <bits/stdc++.h>

using namespace std;


ifstream fin("arbint.in");
ofstream fout("arbint.out");

int n,m;
int maxArb[4*100101];

void Update(int nod, int left, int right, int pos, int val)
{
    if(left == right)
    {
        maxArb[nod] = val;
        return;
    }
    int div = (left + right ) / 2;
    if(pos <= div) Update(2*nod,left,div,pos,val);
        else Update(2*nod+1,div+1,right,pos, val);

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

}

void Query(int nod, int left, int right, int &maxim, int a, int b)
{
    if(a <= left && right <= b)
    {
        if(maxim < maxArb[nod])
            maxim = maxArb[nod];
        return;
    }

    int div = (left + right) / 2;
    if(a <= div) Query(2*nod,left,div,maxim,a,b);
    if(div < b) Query(2*nod+1,div+1,left,maxim,a,b);
}

int main()
{
    int x, a, b;

    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)
        {
            int maxim = -1;
            Query(1,1,n,maxim,a,b);
            fout << maxim << "\n";
        }
        else
        {
            Update(1,1,n,a,b);
        }

    }
    return 0;
}