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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {
    static long ans = 1001001001001001018L;;
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();
        divisorList(n);
        System.out.println(ans);
    }
        
    public static List<Long> divisorList(long n) {
        List<Long> res = new ArrayList<Long>();
        for (long i = 1; i * i <= n; i++) {
            if (n % i == 0) {
                res.add(i);
                
                long j = n / i;
                if (j != i) {
                    res.add(j);
                    
                    String s = String.valueOf(i);
                    String t = String.valueOf(j);
                    ans = Math.min(ans, Math.max(s.length(), t.length()));
                } else {
                    String u = String.valueOf(i);
                    ans = Math.min(ans, u.length());
                }
            }
        }
        res.sort(Comparator.naturalOrder());
        
        return res;
    }
}