#include <iostream>
using namespace std;
int main(){
  string s,x;
  cin>>s;
  for(int i=0; i<s.size(); ++i){
    if(s[i]>=65 && s[i]<=90){
      char c;
      c=s[i];
      c+=32;
      x+=c;
    } else if(s[i]>=97 && s[i]<=122){
      char c;
      c=s[i];
      c-=32;
      x+=c;
    } else {
      x+=s[i];
    }
  }
  cout<<x<<endl;
  return 0;
}