A matrix is constructed of size n*n. such that M_{i}_{,j}= i+j. Count the number of cells having value q.
Note: Assume, the array is in 1-based indexing.

Example 1:
Input:
n = 4, q = 7
Output:
2
Explanation:
Matrix becomes
2 3 4 5
3 4 5 6
4 5 6 7
5 6 7 8
The count of 7 is 2.
Example 2:
Input:
n = 5, q = 4
Output:
3
Explanation:
Matrix becomes
2 3 4 5 6
3 4 5 6 7
4 5 6 7 8
5 6 7 8 9
6 7 8 9 10
The count of 4 is 3.

Your Task:
You don't need to read input or print anything. Your task is to complete the function sumMatrix() which takes 2 Integers n, and q as input and returns the count of q in the n*n matrix.

Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)

Constraints:
1 ≤ n,q ≤ 10^{18}

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