#include <iostream>	
#include <stdlib.h>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <string>
using namespace std;
char changeCase(char a){
	if( 97 <= a && a <= 122) return (char)( a - ('a' - 'A'));
	if( 65 <= a && a <= 90) return (char)( a + ('a' - 'A'));
	return a;
}

int main()
{	
	string str;
	cin >> str;
	for( int i = 0; i < str.length(); i++){
		cout<< changeCase(str[i]);
	}
	return 0;
}