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

N -= 1
if N == 0:
    exit(print(1))

MOD = 998244353

def inverse(n, d):
    return n * pow(d, -1, MOD) % MOD

def matrix(a, b):
    ans = [[0]*len(b[0]) for _ in range(len(a))]
    for i in range(len(a)):
        for j in range(len(b[0])):
            ans[i][j] = sum(a[i][k]*b[k][j] for k in range(len(b)))%MOD
    return ans

dp = [[[0]*T for _ in range(T)]]
for i in range(1, T):
    dp[0][i-1][i] = 1
for i in range(1, K):
    dp[0][0][0] += inverse(1, 6)
    dp[0][0][0] %= MOD
for i in range(K, L):
    dp[0][1][0] += inverse(1, 6)
    dp[0][1][0] %= MOD
for i in range(L, 7):
    dp[0][T-1][0] += inverse(1, 6)
    dp[0][T-1][0] %= MOD

for _ in range(29):
    dp.append(matrix(dp[-1], dp[-1]))

ans = [[0] for _ in range(T)]
ans[0][0] = 1
for i in range(30):
    if 1<<i & N:
        ans = matrix(dp[i], ans)

print(ans[0][0])