Problem in posting code in java

i have solved the problem on Factorial , however i don't know how to submit the code i.e. which class should i use? I submitted the code using Main class and i got Time Limit Exceeded error
my code is :

import java.math.BigInteger;
public class Main
{
     public BigInteger factorial(BigInteger n)
    {
        if(n.compareTo(BigInteger.ONE)<=0)
            return new BigInteger("1");
        else
            return n.multiply(factorial(n.subtract(new BigInteger("1"))));
    }
    public static void main(String args[]) throws java.lang.Exception
    {
        int count=0;
        java.io.BufferedReader br = new java.io.BufferedReader(new java.io.InputStreamReader(System.in));
        BigInteger n1 = new BigInteger("10");
        Main m = new Main();
        int cases = Integer.parseInt(br.readLine());
        for(int i=0;i<cases;i++)
        {
            BigInteger n=new BigInteger(br.readLine());
             BigInteger fact=m.factorial(n);
             while(fact.divide(n1).compareTo(BigInteger.ZERO)>0)
             {
                 BigInteger y = fact.remainder(n1);
                 if(y.compareTo(BigInteger.ZERO)==0)
                 {
                 count++;
                 fact=fact.divide(n1);
                 }
                 else
                     break;
              }
            System.out.println(count);
            count = 0; 
        }
}
}