#include <iostream>

using namespace std;

int main() {
    string S;
    cin >> S;
    for(int i = 0; i < S.length(); i++){
        if(S[i] >= 'A' && S[i] <= 'Z'){
            S[i] += 32;
        }else{
            S[i] -= 32;
        }
    }
    cout << S << endl;
    return 0;
}