#include <iostream>
#include <string>
using namespace std;

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

    string res = "";
    for (char c : S) {
        if (isupper(c)) {
            res += tolower(c);
        } else {
            res += toupper(c);
        }
    }
    
    cout << res << endl;
}