class CP:
    def __init__(self, N):
        self.fact = [1]*(N+1)
        self.fact_inv = [1]*(N+1)
        for i in range(2, N+1):
            self.fact[i] = self.fact[i-1]*i%MOD
        self.fact_inv[N] = pow(self.fact[N], -1, MOD)
        for i in reversed(range(1, N)):
            self.fact_inv[i] = self.fact_inv[i+1]*(i+1)%MOD
    def C(self, N, K):
        if N < 0 or K < 0 or N < K:
            return 0
        return self.fact[N]*self.fact_inv[K]%MOD*self.fact_inv[N-K]%MOD
    def P(self, N, K):
        if N < 0 or K < 0 or N < K:
            return 0
        return self.fact[N]*self.fact_inv[N-K]%MOD
    def H(self, N, K):
        if N < 0 or K < 0:
            return 0
        if N == K == 0: return 1
        return self.C(N+K-1, K)

MOD = 998244353
cp = CP(10**7*2)

N, M, K, L = map(int, input().split())

ans = cp.H(N, K*M)
for i in range(1, N+1):
    if K*M < (M+1)*i: break
    if i%2 == 1:
        ans -= cp.C(N, i)*cp.H(N, K*M-(M+1)*i)%MOD
        ans %= MOD
    else:
        ans += cp.C(N, i)*cp.H(N, K*M-(M+1)*i)%MOD
        ans %= MOD

for i in range(L):
    cnt = K*M-i
    SUM = cp.H(N-1, cnt)
    for j in range(1, N):
        if cnt < (M+1)*j: break
        if j%2 == 1:
            SUM -= cp.C(N-1, j)*cp.H(N-1, cnt-(M+1)*j)%MOD
            SUM %= MOD
        else:
            SUM += cp.C(N-1, j)*cp.H(N-1, cnt-(M+1)*j)%MOD
            SUM %= MOD
    ans -= SUM
    ans %= MOD

for i in range(L, M+1):
    cnt = K*M-i
    SUM = cp.H(N-1, cnt)
    for j in range(1, N):
        if cnt < (i+1)*j: break
        if j%2 == 1:
            SUM -= cp.C(N-1, j)*cp.H(N-1, cnt-(i+1)*j)%MOD
            SUM %= MOD
        else:
            SUM += cp.C(N-1, j)*cp.H(N-1, cnt-(i+1)*j)%MOD
            SUM %= MOD
    ans -= SUM
    ans %= MOD

print(ans)