Max Base Pair

You are given an integer array A. There is a function,F for two integers X and Y with another variable B(base).

Now for caluculating the functional value first convert X and Y in Base B and then ith bit of F(X,Y,B) = (X_i+Y_i)%B.

You have to return the maximum functional value possible for any pair of elements of Array A in base B. Please note that you can't take two elements for pair from the same index.

NOTE: Array elements are in base 10 and you have to return your answer also in base 10(calculated value from equation is in base B).

1 <= A.size() <= 10⁶

2 <= A[i] <= 10⁶

2 <= B <= 9

First argument is a vector of integers A.

Second argument is an integer B

Return a single integer showing maximum pair functional value.

Input 1:

10 1 2 3 4 5 6 7 8 9 10
3

Input 2:

5 10 99 88 48 213
7

Output 1:

19

Output 2:

312

Explanation 1:

93 = 100 and 103 = 101
Hence, F(9,10,3) = 2013 = 1910
We may check for other pairs we will get less than or equal to 15.

Explanation 2:

Lets calculate F(i,j,7) for all pairs,
10 99: 109
10 88: 91
10 48: 2
10 213: 223
99 88: 187
99 48: 140
99 213: 312
88 48: 80
88 213: 245
48 213: 205
Clearly maximum value is 312.