TJ

#include<bits/stdc++.h>
using namespace std;

int main()
{
	char ch;
	cin>>ch;
	if(ch <= 'Z' && ch >= 'A') ch = ch - 'A' + 'a';
	else if(ch <= 'z' && ch >= 'a') ch = ch - 'a' + 'A';
	cout<<ch;
	return 0; 
}