Problem: We have a grid with A horizontal rows and B vertical columns, with the squares painted white. On this grid, we will repeatedly apply the following operation:

* Assume that the grid currently has a horizontal rows and b vertical columns. Choose "vertical" or "horizontal".
* If we choose "vertical", insert one row at the top of the grid, resulting in an (a+1) \times b grid.
* If we choose "horizontal", insert one column at the right end of the grid, resulting in an a \times (b+1) grid.
* Then, paint one of the added squares black, and the other squares white.



Assume the grid eventually has C horizontal rows and D vertical columns. Find the number of ways in which the squares can be painted in the end, modulo 998244353.

Constraints

* 1 \leq A \leq C \leq 3000
* 1 \leq B \leq D \leq 3000
* A, B, C, and D are integers.

Input

Input is given from Standard Input in the following format:


A B C D


Output

Print the number of ways in which the squares can be painted in the end, modulo 998244353.

Examples

Input

1 1 2 2


Output

3


Input

2 1 3 4


Output

65


Input

31 41 59 265


Output

387222020

Solution (in PYTHON3):

Solution:
A,B,C,D=map(int,input().split())
dp=[[0]*(D+1) for i in range(C+1)]
m=998244353
dp[A][B]=1
for i in range(C-A):
    dp[A+i+1][B]=dp[A+i][B]*B%m
for j in range(D-B):
    dp[A][B+j+1]=dp[A][B+j]*A%m
for i in range(C-A):
    for j in range(D-B):
        dp[A+i+1][B+j+1]=(dp[A+i][B+j+1]*(B+j+1)+dp[A+i+1][B+j]*(A+i+1)-dp[A+i][B+j]*(A+i)*(B+j))%m
print(dp[-1][-1])