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 CPP):

Solution:
#include <cstdio>

using namespace std;

const int mod = 998244353;

long long dp[3001][3001];

int main() {
    int a, b, c, d, i, j;
    
    scanf("%d %d %d %d", &a, &b, &c, &d);
    
    dp[a][b] = 1;
    for (i = a; i <= c; i++) {
        for (j = b; j <= d; j++) {
            if (i == a && j == b) continue;
            dp[i][j] = (dp[i - 1][j] * j + dp[i][j - 1] * i) % mod;
            dp[i][j] -= dp[i - 1][j - 1] * (i - 1) % mod * (j - 1) % mod;
            if (dp[i][j] < 0) dp[i][j] += mod;
        }
    }
    
    printf("%lld\n", dp[c][d]);
    
    return 0;
}