Determine if we can choose K different integers between 1 and N (inclusive) so that no two of them differ by 1.

import itertools
n,k=map(int,input().split())
num=[int(i) for i in range(1,n+1)]
cnt=0
for x,y in itertools.combinations(num,2):
    if abs(x-y)!=1:
        cnt+=1
if cnt>=k:
    print('YES')
else:
    print('NO')


n,k=map(int,input().split())
i=1
cnt=0
while i<=n:
    cnt+=1
    i+=2

if cnt>=k:
    print('YES')
else:
    print('NO')
