#include <stdio.h>

int main(void){
	int i;
	char s[110];
	scanf("%s", s);
	for(i=0;i<110;i++){
		if(s[i] == '\0'){break;}
		if('a' <= s[i] && s[i] <= 'z'){
			s[i] -= (char)'a';
			s[i] += (char)'A';
		}else{
			s[i] -= (char)'A';
			s[i] += (char)'a';
		}
	}
	
	printf("%s\n", s);
	return 0;
}