#include<bits/stdc++.h>
using namespace std;
string s;
int main(){
	cin>>s;
	int n=s.size();
	for(int i=0;i<n;i++){
		if(s[i]>='a'&&s[i]<='z'){
			s[i]=s[i]+'A'-'a';
		}else if(s[i]>='A'&&s[i]<='Z'){
			s[i]=s[i]+'a'-'A'; 
		}
	}
	cout<<s; 
	return 0;
}