#include<stdio.h>

void str(int n)

{

if(n==1)

printf("A");

else

{

str(n-1);

printf("%c",(char)('A'+n-1)); 

str(n-1);

}

}

int main()

{

int n;

scanf("%d",&n);

str(n);

return 0;

}
/**************************************************************
	Problem: 1474
	User: admin
	Language: C
	Result: Accepted
	Time:23 ms
	Memory:1144 kb
****************************************************************/