#include <iostream>
#include <string>
#include <cctype>

using namespace std;

int main(int argc, char const* argv[]) {
    string password, res = "";

    cin >> password;

    for (int i = 0; i < password.size(); i++) {
        if (isupper(password[i])) {
            res.push_back(tolower(password[i]));
        } else {
            res.push_back(toupper(password[i]));
        }
    }

    cout << res << endl;
    return 0;
}