#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using Graph = vector<vector<int>>;
using ll = long long;
//正解に近いコードはこちらに移しておく
int main() {
    string S;
    cin >> S;
    rep(i,S.size()) {
        //大文字
        if (int(S[i] < 97)){
            S[i] = char(S[i] + 32);
        }
        else {
            S[i] = char(S[i] - 32);
        }
    }
    cout << S << endl;
}