#include<stdio.h>
void main()
{
	int i,n=0;
	for(i = 97;i <= 122;i++){
		printf("%c",i); 
		n++;
		if(n % 13 == 0){
			printf("\n"); 
		} 
	} 
	for(i = 122;i >= 97;i--){
		printf("%c",i); 
		n++;
		if(n % 13 == 0){
			printf("\n"); 
		} 
	} 

   return 0;
}
/**************************************************************
	Problem: 1093
	User: admin
	Language: C
	Result: Runtime Error
****************************************************************/