#include <iostream>
#include <string>
using namespace std;

int main() {
    string s;
    cin >> s;
    for (int i=0; i<=s.size(); ++i) {
        if (islower(s[i])) {
            cout << (char)toupper(s[i]);
        } 
        else if (isupper(s[i])) {
            cout << (char)tolower(s[i]);
        }
    }
    return 0;
}