？？？

#include <iostream>
#include <cstring>
using namespace std;
int main(){
	char str[32] = {0};
	cin >> str;
	int len = strlen(str);
	for(int i = 0 ; i < len; i++){
		if( str[i] >= 'A' && str[i] <= 'Z')
			str[i] += 32;
		if( str[i] >= 'a' && str[i] <= 'z')
			str[i] -= 32;
	}
	cout << str << endl;
	return 0;
}