# https://yukicoder.me/problems/no/2922

N, S, B = list(map(int, input().split(' ')))
H = list(map(int, input().split(' ')))
mh = H[0]
for i in range(N-1):
    h1, h2 = max(mh, H[i]), H[i+1]
    if not (h1 + S * B) >= h2:
        print('No')
        exit()
print('Yes')