#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int (i)=(0);(i)<(int)(n);++(i))
using ll = long long;
using P = pair<int, int>;
using namespace std;

int main() {
    string s;
    cin >> s;
    rep(i, s.size()) {
        if ('a' <= s[i] and s[i] <= 'z') {
            s[i] -= 0x20;
        }
        else {
            s[i] += 0x20;
        }
    }

    cout << s << endl;
}