#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  string S;
  cin >> S;
  for (int i = 0; i < (int)S.size(); i++) {
    if ('a' <= S[i] && S[i] <= 'z') {
      S[i] = S[i] - 'a' + 'A';
    } else {
      S[i] = S[i] - 'A' + 'a';
    }
  }
  cout << S << '\n';
  return 0;
}