input: Write a python function to find the smallest multiple of all numbers from 1 to n.
  assert smallest_multiple(10) == 2520
  assert smallest_multiple(5) == 60
  assert smallest_multiple(7) == 420
output: def smallest_multiple(n):
      from math import gcd
  
      def lcm(a, b):
          return a * b // gcd(a, b)
  
      result = 1
      for i in range(1, n + 1):
          result = lcm(result, i)
          
      return result