import sys

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

    MAX = N + M * K + 10
    fact = [1] * MAX
    inv = [1] * MAX
    for i in range(1, MAX):
        fact[i] = (fact[i - 1] * i) % MOD
        
    inv[MAX - 1] = pow(fact[MAX - 1], MOD - 2, MOD)
    for i in range(MAX - 2, -1, -1):
        inv[i] = (inv[i + 1] * (i + 1)) % MOD

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

    ans = 0
    total_votes = M * K

    for x in range(L, M + 1):
        min1 = 1
        
        for i in range(N):
            val = (combination(N - 1, i) * ((combination(N - 2 + total_votes - x - (M + 1) * i, N - 2) - combination(N - 2 + total_votes - x - (x + 1) * i, N - 2)) % MOD)) % MOD
            if min1 == 1:
                ans = (ans + val) % MOD
            else:
                ans = (ans - val) % MOD
            
            min1 *= -1

    print(ans % MOD)

if __name__ == "__main__":
    solve()