#include <iostream>
#include <fstream>

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

#define MAXN 100005

int n, m, op, a, b, maxim;
int v[MAXN], arb[4*MAXN+1000];

void update (int nod_crt, int left, int right, int pos, int val)
{
    if(left==right)
    {
        arb[nod_crt]=val;
        return;
    }
    int middle=(left+right)/2;
    if(pos<=middle)
        update(2*nod_crt, left, middle, pos, val);
    else
        update(2*nod_crt+1, middle+1, right, pos, val);

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

void query (int nod_crt, int left, int right, int start, int finish)
{
    if(start<=left && right<=finish)
    {
        if(maxim<arb[nod_crt])
            maxim=arb[nod_crt];
        return;
    }
    int middle=(left+right)/2;
    if(start<=middle)
        query(2*nod_crt, left, middle, start, finish);
    if(middle<finish)
        query(2*nod_crt+1, middle+1, right, start, finish);

}

int main()
{
    fin>>n>>m;
    for(int i=1; i<=n; i++){
        fin>>v[i];
        update(1, 1, n, i, v[i]);
    }
    for(int i=1; i<=m; i++)
    {
        fin>>op>>a>>b;
        if(op==1)
            update(1, 1, n, a, b);
        else{
            maxim=-1;
            query(1, 1, n, a, b);
            fout<<maxim<<"\n";
        }

    }
    return 0;
}