import sys


def debug(*args):
    print(*args, file=sys.stderr)


n, s0, b = map(int, input().split())
h = list(map(int, input().split()))

s = s0
for i in range(n-1):
    if h[i] < h[i+1]:
        diff = h[i+1] - h[i]
        y = (diff+b-1) // b
        if y > s:
            print('No')
            exit()
        # s -= n
        s = s0
    else:
        h[i+1] = h[i]

print('Yes')