#include <stdio.h>
#include <ctype.h>

void main(void){
	char str[53] = {'a'};
	int inputStr = scanf("%s",str);
	if(inputStr == 2){
		printf("strの入力ミス\n");
	}
	int i = 0;
	while(str[i] != '\0'){
		if(isupper(str[i])){
			printf("%c",tolower(str[i]));
		}else{
			printf("%c",toupper(str[i]));
		}
		i++;
	}
	printf("\n");
}