#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

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

  string t = "";
  for (int i = 0; i < s.size(); ++i) {
    if (isupper(s[i])) {
      char tmp = tolower(s[i]);
      t += tmp;
    }
    else {
     char tmp =  toupper(s[i]);
     t += tmp;
    }

  }

  cout << t << "\n";

  return 0;
 
}