#include <iostream>
using namespace std;
int main() {
    string s;
    cin >> s;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] >= 'a')
            s[i] -= 'a' - 'A';
        else
            s[i] += 'a' - 'A';
    }
    cout << s << endl;
    return 0;
}