#include"bits/stdc++.h" using namespace std; char a='A',b='A'-1; int main(){ int n; cin>>n; for(int i=1;i<=n;i++){ b++; if(b>'Z')b='A'; a=b; for(int j=1;j<=n;j++){ cout<<a; a+=1; if(b>'Z')a='A';} cout<<endl;}}