//
//  main.cpp
//  Q339
//
//  Created by AkihiroKOBAYASHI on 7/5/15.
//  Copyright (c) 2015 Akhr5884. All rights reserved.
//

#include <iostream>

int main(int argc, const char * argv[]) {
    using namespace std;
    
    string moji;
    cin >> moji;
    int i;
    
    for(i = 0; i < moji.size(); i++) {
        if('a' <= moji[i] && moji[i] <= 'z'){
            moji[i] = moji[i] - 'a' + 'A';
        }
        else if('A' <= moji[i] && moji[i] <= 'Z'){
            moji[i] = moji[i] - 'A' + 'a';
        }
    }

    cout << moji << "\n";
    
    return 0;
}