X, Y = gets.split.map(&:to_i)
N = gets.to_i
A = gets.split.map(&:to_i)

vx = Rational(X, 3600)
vy = Rational(Y, 3600)

if N <= 1
  puts 'YES'
else
  t = Rational(A[-2], vx)
  d = t * vy - A[-2]

  if A[-1] - A[-2] < d
    puts 'NO'
  else
    puts 'YES'
  end
end