Hi, here's your problem today. This problem was recently asked by Microsoft:

Return the longest run of 1s for a given integer n's binary representation.

Example:
Input: 242
Output: 4
242 in binary is 0b11110010, so the longest run of 1 is 4.

<pre lang=py>
def longest_run(n):
  # Fill this in.

print longest_run(242)
# 4
</pre>