output_description: The number of totatives in a line.
input_description: n
      
  
  An integer n (1 ≤ n ≤ 1000000000).
attempt: p = n = int(input())
  d = 2
  while d * d <= n:
      if n % d == 0:
          p = p * (d - 1) // d
          while n % d == 0:
              n //= d
      d += 1
  if n > 1:
      p = p * (n - 1) // n
  print(p)
  
problem_description: Euler's Phi Function
  
    
  
  For given integer n, count the totatives of n, that is, the positive integers
  less than or equal to n that are relatively prime to n.
samples: [{"input": "6", "output": "2"}, {"input": "1000000", "output": "400000"}]