#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;


int main() {

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

    cout << S << endl;

    return 0;
}