#include <bits/stdc++.h>

using namespace std;

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

    for (int i = 0; i < s.length(); ++i) {
        if (islower(s[i])) {
            s[i] = toupper(s[i]);
        } else {
            s[i] = tolower(s[i]);
        }
    }

    cout << s << endl;
    return 0;
}