#include <iostream>
#include <cctype>
using namespace std;

int main ()
{
	char input;
	cout << "Enter the variable : ";
	cin.get(input) ;

	if (isdigit(input))
		cout << "digit" << endl;
	else if (isalpha(input))
		cout << "letter" << endl;
	else 
	cout << "special character" << endl;
	return 0;
	
}