#!/usr/bin/ruby
a,b=gets.split.map(&:to_i).sort
if b==0
	p 0
#elsif a==0
#	gets;p $<.count{|e|x,y=e.split.map &:to_i;x%b==0&&y%b==0}
else
	g=b.gcd a
	gets;p $<.count{|e|x,y=e.split.map{|e|e.to_i.abs%g}.sort;x==0&&y%(b-a)==0}
end