#include<iostream>
using namespace std;
int main(){
    char ch;
    if(!(cin>>ch)) return 0;
    if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='z')){
        cout<<"alphabet"<<endl.;
    
    }
    else if(ch>='0'&&ch<='9'){
        cout<<"digit"<<endl;
    }
    else{
        cout<<"special character"<<endl;
    }
    return 0;
}