#include <iostream>
using namespace std;
int main() {
    string s; cin >> s;
    for (char c : s) {
        if ('A' <= c && c <= 'Z') {
            char a = 'a' + (c - 'A');
            cout << a;
        }
        else {
            char a = 'A' + (c - 'a');
            cout << a;
        }
    }
    cout << endl;
}