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())

MOD = 998244353

dp = [[1]*C for _ in [0]*D]

if B<D:
    dp[B][A-1] = A
for i in range(B+1,D):
    j = A-1
    dp[i][j] = dp[i-1][j]*A %MOD
if A < C:
    dp[B-1][A] = B
for j in range(A+1,C):
    i = B-1
    dp[i][j] = dp[i][j-1]*B %MOD

for i in range(B,D):
    for j in range(A,C):
        dp[i][j] = dp[i-1][j]*(j+1) + dp[i][j-1]*(i+1) -dp[i-1][j-1]*i*j
        dp[i][j] %= MOD

print(dp[-1][-1])