AC,GO!

简单！

#include<iostream>
#include<cctype>
using namespace std;
int main(){
    char a;
    cin>>a;
    if(isalnum(a))
    {
        if(isalpha(a)){
            if(isupper(a)) cout<<"A";
            else cout<<"a";
        }
        else cout<<"0";
    }
    else cout<<"other";
    return 0;
}