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

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