#include <iostream>
#include <string>

using namespace std;

int main() {
  string s;
  char c;
  cin >> s;

  for (int i = 0; i < (int)s.size(); i++){
    c = s[i];
    if (isupper(c)){
      s[i] = tolower(c);
    } else {
      s[i] = toupper(c);
    }
  }
  cout << s << endl;
  return 0;
}