#include <iostream>
using namespace std;

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

    for (int i = 0; i < S.length(); i++) {
        char x = S.at(i);
        cout << char((x >= 65 && x <= 90) ? x + 32 : x - 32);
    }
    cout << endl;

    return 0;
}