mod = 998244353
N = int(input())
M = int(input())
X = int(0)

def factorialmod(n,mod):
    Y = int(1)
    for _ in range(1,n+1):
        Y = (Y*_)%mod
    return Y


def cmb(n,r,mod):
    if n == 0:
        return 0
    if n<r:
        return "error"
    else:
        return int(factorialmod(n,mod)/(factorialmod(r,mod)*factorialmod(n-r,mod)))


for _ in range(0,N-M+1):
    X += cmb(N,M+_,mod)%mod