Description: You are given a positive integer n. Output the number of trailing zeros in n! (n! denotes a product of integers between 1 and n, inclusive). Input Format: The only line of input contains an integer n (1 ≤ n ≤ 1000000). Output Format: Output the number of trailing zeros in n!. Note: In the first sample 6! = 720. In the second sample 24! = 620448401733239439360000.