/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		long n = 2432902008176640000L;
        while (n > 9999) {
          n = n / 10;
        }
		System.out.println(n);
	}
}