https://www.acmicpc.net/problem/22869
n, k = map(int, input().split())
mlist=list(map(int, input().split()))
dp=[0]*(n)
dp[0]=1
for i in range(n-1):
if dp[i]==0:
continue
for j in range(i+1,n):
jump=(j-i)*(1+abs(mlist[i]-mlist[j]))
if jump<=k:
dp[j]=1
if dp[-1]==1:
print("YES")
else:
print("NO")