// yukicoder: No.163 cAPSlOCK
// 2019.4.12 bal4u

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

char s[105], *p;

int main()
{
	scanf("%s", &s);
	p = s; while (*p) {
		if (isupper(*p)) *p = tolower(*p);
		else *p = toupper(*p);
		p++;
	}
	puts(s);
	return 0;
}