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

int main(void)
{
	char S[100];
	scanf("%s",S);
	for(int i=0;i<100;i++) {
		if('a'<=S[i] && S[i]<='z') {
			S[i]=S[i]-('a'-'A');
		}else if('A'<=S[i] && S[i]<='Z')
			S[i]=S[i]+('a'-'A');
	}
	printf(S);
return 0;
}