#include <stdio.h>
#include <string.h>

int main(void)
{
	char s[101];
	scanf("%s", s);
	for (int i = 0; i < strlen(s); i++) {
		if ('A' <= s[i] && s[i] <= 'Z') s[i] += 32;
		if ('a' <= s[i] && s[i] <= 'z') s[i] -= 32;
	}
	printf("%s\n", s);
	return 0;
}