开荒

#include<iostream>
#include<cstring>
using namespace std;
int main(){
    char a;
    cin >> a;
    if(a>='a'&& a<='z')
        cout<< char(a-32);
    else if(a>='A'&&a<='Z')
        cout<< char(a+32);
    else
        cout << a;
}