Problem Statement

You are given an integer N.
For two positive integers A and B, we will define F(A,B) as the larger of the following: the number of digits in the decimal notation of A, and the number of digits in the decimal notation of B.
For example, F(3,11) = 2 since 3 has one digit and 11 has two digits.
Find the minimum value of F(A,B) as (A,B) ranges over all pairs of positive integers such that $N = A \times B$.

Input

The input is given from Standard Input in the following format:
N

Output

Print the minimum value of F(A,B) as (A,B) ranges over all pairs of positive integers such that $N = A \times B$.

Constraints

• $1 \leq N \leq 10^{10}$
• N is an integer.

Sample Input 1

10000

Sample Output 1

3

F(A,B) has a minimum value of 3 at (A,B)=(100,100).

Sample Input 2

1000003

Sample Output 2

7

There are two pairs (A,B) that satisfy the condition: (1,1000003) and (1000003,1). For these pairs, F(1,1000003)=F(1000003,1)=7.

Sample Input 3

9876543210

Sample Output 3

6

见题面 Input 部分

见题面 Output 部分