#include <iostream>
#include <string>

using namespace std;

int main() {
  string s;
  cin >> s;
  for (auto &c:s) {
    if (c>='A' && c<='Z') {
      c+=32;
    } else {
      c-=32;
    }
  }

  cout << s << endl;
  return 0;
}