#include <iostream>
#include <string>
using namespace std;

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