#include <bits/stdc++.h>

#define rep(i, n) for (int (i) = 0; (i) < (int)(n); (i)++)

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;

int main() {
    string s;
    cin >> s;
    int n = s.size();
    for (int i = 0; i < n; i++) {
        if ('A' <= s[i] && s[i] <= 'Z') {
            cout << (char)(s[i] - 'A' + 'a') ;
        } else {
            cout << (char)(s[i] - 'a' + 'A');
        }
    }
    cout << endl;
    return 0;
}