n,k = map(int, input().split())
if n==1 or n==2:
    if k==1:
        print('YES')
    else:
        print('NO')
elif n%2==0:
    cnt = n/2
    if(cnt>=k):
        print('YES')
    else:
        print('NO')
else:
    cnt = n//2 + 1
    if(cnt>=k):
        print('YES')
    else:
        print('NO') n,k = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split k if n==1 or n==2:
    if k==1:
        print('YES')
    else:
        print('NO')
elif n%2==0:
    cnt = n/2
    if(cnt>=k):
        print('YES')
    else:
        print('NO')
else:
    cnt = n//2 + 1
    if(cnt>=k):
        print('YES')
    else:
        print('NO') n==1 or n==2 n==1 n 1 n==2 n 2 if k==1:
        print('YES')
    else:
        print('NO') k==1 k 1 print('YES') print 'YES' print('NO') print 'NO' elif n%2==0:
    cnt = n/2
    if(cnt>=k):
        print('YES')
    else:
        print('NO') n%2==0 n%2 n 2 0 cnt = n/2 cnt n/2 n 2 if(cnt>=k):
        print('YES')
    else:
        print('NO') cnt>=k cnt k print('YES') print 'YES' print('NO') print 'NO' cnt = n//2 + 1 cnt n//2 + 1 n//2 n 2 1 if(cnt>=k):
        print('YES')
    else:
        print('NO') cnt>=k cnt k print('YES') print 'YES' print('NO') print 'NO' cnt = n/2 n/2 cnt cnt = n//2 + 1 n//2 + 1 cnt n,k = map(int, input().split()) map(int, input().split()) n k = map(int, input().split()) map(int, input().split()) k
n,k = map(int, input().split())
if n==1 or n==2:
    if k==1:
        print('YES')
    else:
        print('NO')
elif n%2==0:
    cnt = n/2
    if(cnt>=k):
        print('YES')
    else:
        print('NO')
else:
    cnt = n//2 + 1
    if(cnt>=k):
        print('YES')
    else:
        print('NO')