Codeforces#291 Div2-B

291-div2-b.rb

# http://codeforces.com/contest/514/problem/B
require 'set'

n, x0, y0 = gets.split.map(&:to_f)

set = Set.new
n.to_i.times do
  x, y = gets.split.map(&:to_f)

  if x == x0
    set << true
  else
    set << (y - y0) / (x - x0)
  end
end

puts set.length