n,s,b = map(int, input().split())

hlist = [0] + list(map(int, input().split()))

stack = [s*b]

for i in range(1,n+1):
    h = hlist[i]
    while stack:
        if stack[-1] < h:
            stack.pop()
        else:
            break

    if stack:
        stack.append((h+s*b))
    else:
        print("No")
        exit()

print("Yes")