#include <iostream>
#include <string>

using namespace std;

int main() {
    string s;
    cin >>s;
    for (size_t i = 0; i < s.size(); ++i) {
        if (s.at(i) < 91) {
            s.at(i) = static_cast<char>(s.at(i) + 32);
        } else {
            s.at(i) = static_cast<char>(s.at(i) - 32);
        }
    }
    cout << s << endl;
    return 0;
}