#include <bits/stdc++.h>
using namespace std;

int main(){
   string s;
   cin >> s;
   
   for(int i = 0; i < s.size(); i++){
       if(s.at(i) <= 'a'){
           s.at(i) = towlower(s.at(i));
       }else{
           s.at(i) = toupper(s.at(i));
   }
   }
   cout << s;
}