#include <iostream>
#include <string>
#include <cctype>
using namespace std;
int main() {
	string s, ans;
	cin >> s;
	for (auto c : s) {
		if (isupper(c) != 0)ans.push_back((char)(c + 32));
		if (islower(c) != 0)ans.push_back((char)(c - 32));
	}
	cout << ans << endl;
}