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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>
#include <map>
#include <cstdio>
#include <cstring>
#include <math.h>
#include <bitset>
#include <time.h>
#include <set>
#include <algorithm>
#define MAXN 100000
#define ll long long
using namespace std;


ll D(ll x) {
    int ct=0;
    while(x) {
       ct++;
        x/=10;
    }
    return ct;
}
int main() {
    ll N;
    cin>>N;
    ll ans=N+100;
    for(ll x=1;x*x<=N;x++) {
        if (N%x==0) {
            ans = min(ans, max(D(x),D(N/x)));
        }
    }
    
    cout << ans << endl;
    
}