#include <bits/stdc++.h>
using namespace std;

int main () {

    string S;
    cin >> S;

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

    return 0;
}