A number n is apocalyptic if 2^n contains a string of 3 consecutive 6s (666 being the presumptive "number of the beast").
Create a function that takes a number n as input. If the number is apocalyptic, find the index of 666 in 2^n, and return "Repent! X days until the Apocalypse!" (X being the index). If not, return "Crisis averted. Resume sinning.".
apocalyptic(109) ➞ "Crisis averted. Resume sinning."
apocalyptic(157) ➞ "Repent! 9 days until the Apocalypse!"
# 2^157 -> 182687704666362864775460604089535377456991567872
# 666 at 10th position (index 9)
apocalyptic(175) ➞ "Crisis averted. Resume sinning."
apocalyptic(220) ➞ "Repent! 6 days until the Apocalypse!"
N/A