#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
  string s;
  cin>>s;
  for(int i=0;i<(int)s.size();i++){
    if(islower(s[i])) s[i]+='A'-'a';
    else if(isupper(s[i])) s[i]+='a'-'A';
  }
  cout<<s<<endl;
  return 0;
}