import sequtils, strutils

let
  xy = stdin.readLine.split.map parseFloat
  x = xy[0] * 1000 / (60 * 60)  # m/s
  y = xy[1] * 1000 / (60 * 60)
  _ = stdin.readLine
  a = stdin.readLine.split.map parseFloat

for i, dist in a:
  if i.succ > a.high: break
  let time = dist / x
  if time * y > a[i.succ] + 0.00001:
    echo "NO"
    echo time * y
    echo a[i.succ]
    quit()

echo "YES"