#include <iostream>
#include <string>
using namespace std;
int main() {
string s;
char q='a';
int n,k,i,j;
cin >> n;
for (i=0, k=n-1; i<n; i++, k--) {
s=s+q;
q++;
cout << 'a';
for (j=0; j<k; j++) cout << " ";
cout << s << "\n";
}
return 0;
}
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