#include<iostream>                        
 
using namespace std;
 
int main(){
  char buff[101]={'a'};
  int i = 0;
 
  cin >> buff;
 
  while(buff[i]!=0 && i < 100){
    int num = int(buff[i]);
 
    //cout<<num;
 
    if(num >= 65 && num <= 90){
      cout<<char(num+32);
    }else if(num >= 97 && num <= 122){
      cout<<char(num-32);
    }else{
      cout<<buff[i];
    }
    i++;
    //cout << endl;
  }
  return 0;
}