output_description: Print the minimum value of F(A,B) as (A,B) ranges over all pairs of positive
  integers such that N = A \times B.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N
attempt: def f(a,b):
    digit_a = digit_b=0
    
    while a:
      digit_a+=1
      a//=10
      
    while b:
      digit_b+=1
      b//=10
      
    return max(digit_a, digit_b)
  
  n = int(input())
  
  ans = n
  for i in range(1, int((n+1)**0.5)):
    for n%i==0:
      n = min(n, f(i, n//i))
      
  print(ans)
      
problem_description: 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.
samples: [{"input": "10000", "output": "3\n    \n\nF(A,B) has a minimum value of 3 at (A,B)=(100,100).\n\n* * *"}, {"input": "1000003", "output": "7\n    \n\nThere are two pairs (A,B) that satisfy the condition: (1,1000003) and\n(1000003,1). For these pairs, F(1,1000003)=F(1000003,1)=7.\n\n* * *"}, {"input": "9876543210", "output": "6"}]