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#include <fstream>
#include <vector>
using namespace std;
ifstream cin("arbint.in");
ofstream cout("arbint.out");
int n,m,x;
vector<int> A;
void Update(int st,int dr,int poz,int val,int nod)
{
    if(st==dr)
    {
     A[nod]=val;
     return;
    }
    int mij=st+(dr-st)/2;
    if(poz<=mij)
    Update(st,mij,poz,val,2*nod);
    else
    Update(mij+1,dr,poz,val,2*nod+1);
    A[nod]=max(A[2*nod],A[2*nod+1]);
}
int Compute(int st,int dr,int a,int b,int nod)
{
    if(b<st || dr<a)
      return -1;
    if(st>=a && dr<=b)
      return A[nod];
    int mij=st+(dr-st)/2;
    return max(Compute(st,mij,a,b,2*nod),Compute(mij+1,dr,a,b,2*nod+1));
}
int main()
{
    cin>>n>>m;
    A.resize(4*n+1);
    for(int i=1;i<=n;i++)
      {
          cin>>x;
          Update(1,n,i,x,1);
      }
    for(int i=1;i<=m;i++)
    {
        bool ok;
        int a,b;
        cin>>ok>>a>>b;
        if(ok==1)
            Update(1,n,a,b,1);
        else
          cout<<Compute(1,n,a,b,1)<<'\n';
    }
    return 0;
}