X, Y = map(int, input().split())
X = X * 10 / 36
Y = Y * 10 / 36

N = int(input())
A = list(map(int, input().split()))

B = [0]
for a in A:
    t = a / X
    B += [t * Y]

ans = 'YES'
for a, b in zip(A, B):
    if a < b:
        ans = 'NO'

print(ans)