Problem:
Score : 300 points

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.

Constraints

1 \leq N \leq 10^{10}

N is an integer.

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.

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

Solution in C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <math.h>

int counter( long long int n ){
    int count = 0;
    while( n > 0 ){
        n = n/10;
        count++;
    }
    return count;
}

int main(void){
    
    long long int i,n;
    int a,b,ans=1;
    
    scanf( "%lld",&n );
    
    for( i = 1; i <= sqrt((double)n); i++ ){
        if( n % i == 0 ){
            a = counter(i);
            b = counter(n/i);
            if( a > b ) ans = a;
            else ans = b;
        }
    }
    printf( "%d\n",ans );

    return 0;
}