#include <stdio.h>


int main()
{
	char real[101];
	int i;

	scanf("%s", real);
	for (i = 0; real[i] != '\0'; i++) {
		if (real[i] >= 'A' && 'Z'>=real[i]) {
			real[i] +='a'-'A';
		}
		else {
			real[i] -= 'a'-'A';
		}
	}
	printf("%s\n", real);

	return 0;
}