n,t=map(int,input().split())
k,l=map(int,input().split())
M=998244353
L=t

def seki(a,b):
  c=[[0]*L for i in range(L)]
  for i in range(L):
    for j in range(L):
      for k in range(L):
        c[i][j]+=a[i][k]*b[k][j]
        c[i][j]%=M
  return c

A=[[0]*L for i in range(L)]
A[0][1-1]=(k-1)*pow(6,M-2,M)%M
A[0][2-1]=(l-k)*pow(6,M-2,M)%M
A[0][t-1]=(6-l+1)*pow(6,M-2,M)%M
for i in range(L-1):
  A[i+1][i]=1

B=[[0]*L for i in range(L)]
for i in range(L):
  B[i][i]=1

for i in range(30):
  if ((n-1)>>i)&1:
    B=seki(A,B)
  A=seki(A,A)

print(B[0][0])