#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>
#include <cstdlib>

using namespace std;

int main() {
	string s;
	cin >> s;

	for (int i = 0; i < s.size(); i++) {
		s[i] =  ('a' <= s[i] && s[i] <= 'z') ? toupper(s[i]) : tolower(s[i]);
	}
	cout << s << endl;
	return 0;
}