#include <stdio.h>


int main(void)
{
	char str[101];
	int i = 0;
	scanf("%s", str);

	/*A=65 Z=90 a=97 z=122*/
	while (str[i] != '\0') {
		if ((int)str[i] >= 65 && 90 >= (int)str[i]) {
			str[i] = (int)str[i] + 32;
		} else if ((int)str[i] >= 97 && 122 >= (int)str[i]) {
			str[i] = (int)str[i] - 32;
		}
		i++;
	}
	printf("%s", str);
	
	return 0;
}