Enormous Input Test timeout…. but why?

Hi guys.

Having a problem with Enormous Input Test, and after 10 hours of trying to figure it out, I'm no better off.

Here's my code - I get a timeout.

import sys
a1 = raw_input().split(' ')
b1 = int(a1[0])
b2 = int(a1[1])
i=0
a4 = 0
while i < b1 :
    if((int(sys.stdin.readline().strip()) % b2) == 0):
        a4+=1
    i+=1
print a4