SPOJ Brasil

Factorial of a number N can be defined as: N! = 1 * 2 * 3 * 4 * ..... * (N-1) * N.
Also 0! = 1.

As this could be large number, So we don't want you to calculate it. Instead you are given factorial of a number and you have to predict the number.

Input

The first line of input contain n!.

Constraints

• 2 ≤ n!
• 1 ≤ d ≤ 10⁶ (d is total number of digits in the n!)

Output

For each given n! print value of n.

Example

Input:
24

Output:
4

Input:
51090942171709440000

Output:
21

Input:
10888869450418352160768000000

Output:
27