#include <algorithm>
#include <iostream>
#include <string>

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

    std::transform(std::begin(s), std::end(s), std::begin(s), [](char c) {
        if (std::isupper(c)) {
            return std::tolower(c);
        }
        return std::toupper(c);
    });
    std::cout << s << std::endl;
}