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

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