// No.163 cAPSlOCK
#include <iostream>
#include <string>
#include <cctype>
using namespace std;

int main() {
    string s;
    cin >> s;
    for (auto c: s) {
        if (islower(c)) cout << (char)toupper(c);
        else cout << (char)tolower(c);
    }
    cout << endl;
}