#include <iostream>

using namespace std;

int main() {
    string s;
    
    cin >> s;
    
    for (int i = 0; i < s.length(); i++) {
        if (65 <= s[i] && s[i] <= 90) {
            s[i] += 32;
        } else {
            s[i] -= 32;    
        }
    }
    
    cout << s << endl;
    
    return 0;
}