#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;
}

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