#include <stdio.h>
#include <stdlib.h>
int main(void) 
{
	char grade;
	scanf("%c",&grade);
	printf("Input grade:%c\n",grade);
	
	switch(grade)
	{
		case 'a':
		case 'A':
		printf("牛逼");
		break;
		
		case 'b':
		case 'B':
		printf("可");
		break;
		
		case 'c':
		case 'C':
		printf("加油");
		break;
		
		default:
		printf("無成績");
		
	}
	return 0;
}