def extgcd(a, b)
    if b == 0
        {x: 1, y: 0, gcd: a}
    else
        prev = extgcd(b, a % b)
        {
            x: prev[:y],
            y: prev[:x] - (a / b) * prev[:y],
            gcd: prev[:gcd]
        }
    end
end

a, b, c, d = gets.split.map(&:to_i)
gx = a.gcd(c);
dy0 = (c*b-a*d).abs / gx

hash = extgcd(a/gx, c/gx)
dy1 = hash[:x]*b + hash[:y]*d

result = {}
N = gets.to_i
N.times do
    x, y = gets.split.map(&:to_i)
    x2 = x % gx
    y2 = y - (x-x2)/gx*dy1
    y2 %= dy0 if dy0 > 0
    result[[x2, y2]] = true
end
puts result.size