/**
*    author:  boutarou
*    created: 02.08.2020 11:20:06
**/

#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>;

int main() {
    string s;
    cin >> s;
    rep(i,s.size()) {
        if (islower(s[i])) s[i] = toupper(s[i]);
        else s[i] = tolower(s[i]);
    }
    cout << s << endl;
    return 0;
}