N, S, B = map(int, input().split())
H = list(map(int, input().split()))

A = [H[0]]
for i in range(1, N):
    if A[-1] <= H[i]:
        A.append(H[i])

for i in range(len(A)-1):
    if A[i+1]-A[i] > B*S:
        print("No")
        break
else:
    print("Yes")