#include <bits/stdc++.h>

using namespace std;

int main() {
	string s;
	cin >> s;
	for (int i = 0;i < s.size();i++) {
		if (s[i] >= 'a'&&s[i] <= 'z') {
			s[i] = toupper(s[i]);
		}
		else {
			s[i] = tolower(s[i]);
		}
	}
	cout << s;

	return 0;
}