import sys

def solve():
    N, M, K, L = map(int, input().split())
    
    MOD = 998244353

    MAX = N + M * K + 10
    fact = [1] * (MAX + 1)
    factinv = [1] * (MAX + 1)
    inv = [1] * (MAX + 1)

    for p in range(1, MAX + 1):
        fact[p] = (fact[p - 1] * p) % MOD
        if p > 1:
            inv[p] = (-(MOD // p) * inv[MOD % p]) % MOD
        factinv[p] = (factinv[p - 1] * inv[p]) % MOD

    def combination(n, r):
        if r < 0 or n < 0 or r > n:
            return 0
        return (fact[n] * ((factinv[r] * factinv[n - r]) % MOD)) % MOD

    ans = 0

    m = [0] * N
    for i in range(0, N):
        m[i] = combination(N - 1, i)

    for x in range(L, M + 1):
        min1 = 1
        c = N - 2 + M * K - x
        
        for i in range(0, N):
            val = (m[i] * ((combination(c - (M + 1) * i, N - 2) - combination(c - (x + 1) * i, N - 2)) % MOD)) % MOD
            ans = (ans + val * min1) % MOD
            
            min1 *= -1

    print(ans % MOD)

if __name__ == "__main__":
    solve()