#include <iostream>

int B = 2;
int N = 4;

int main() {
   int integerArray1[4][4] = {
      {1,1,2,3},
      {4,5,6,7},
      {8,9,0,1},
      {2,3,4,5}};
   int integerArray2[4][4] = {
      {4,1,2,3},
      {4,5,6,7},
      {8,9,0,1},
      {2,3,4,5}};
   int productArray[4][4] = {
      {0,0,0,0},
      {0,0,0,0},
      {0,0,0,0},
      {0,0,0,0}};

      for (int kk = 0 ; kk < N*B; kk++)
         for (int jj = 0; jj < N*B; jj++)
            for (int i = 0; i < N; i++)

               for (int k = kk; k < std::min(kk+B-1, N); k++)
               {
                  int r = integerArray1[i][k];
                  for (int j = jj; j < std::min(jj+B-1, N); j++)
                     productArray[i][j] += r*integerArray2[k][j];
               }

   for (int z = 0; z < 4; z++)
   {
      for (int y = 0; y < 4; y++)
      {
         std::cout << productArray[z][y] << ", ";
      }
      std::cout << "\n";
   }
}