#include <iostream>
using namespace std;
int main() {
	char s[100];
	cin >> s;
	for (int i = 0; s[i] != '\0'; i++) {
		if (s[i] >= 'a'&&s[i] <= 'z') {
			s[i] = (char)((int)s[i] - 32);
		}
		else if (s[i] >= 'A'&&s[i] <= 'Z') {
			s[i] = (char)((int)s[i] + 32);
		}
	}
	cout << s << endl;
}