#include <bits/stdc++.h>
using namespace std;

int main() {
  string s;

  cin >> s;
  for (int i = 0; i < (int)s.size(); i++) {
    if (islower(s[i])) {
      s[i] = toupper(s[i]);
    } else {
      s[i] = tolower(s[i]);
    }
  }
  cout << s << endl;
}