#!/usr/bin/env python
# coding: utf-8

# We just need to find the [lcm](https://en.wikipedia.org/wiki/Least_common_multiple).

# In[6]:


from math import gcd

def lcm(a, b):
    return a*b // gcd(a, b)

l = 1
for n in range(1,20+1):
    l = lcm(l, n)
l


# In[ ]: