#include <stdio.h>

#define BUFSIZE 10000

int main(int argc, char **argv) {
	char buff[BUFSIZE];

	while (fgets(buff, BUFSIZE, stdin)) {
		int i;
		for (i = 0; buff[i]; i++) {
			if ( buff[i] >= 'a' && buff[i] <= 'z' )
				buff[i] = buff[i] - 'a' + 'A';
			else if ( buff[i] >= 'A' && buff[i] <= 'Z' )
				buff[i] = buff[i] - 'A' + 'a';
		}
		fputs(buff, stdout);
	}

	return 0;
}