#include <iostream>

void main()
{ int A[6][4] = { { 3, 5, 1, 2 },
                  { 4, 2, 1, 5 },
                  { 2, 4, 6, 1 },
                  { 1, 2, 5, 1 },
                  { 3, 0, 1, 0 },
                  { 2, 4, 6, 1 } };

  for (int r = 0; r < 6; r += 1)
  { for (int c = 0; c < 4; c += 1)
      cout << " " << A[r][c];
    cout << "\n"; }
  cout << "Before addition\n";

  A[3][4] = A[6][0] + A[1][4];

  cout << "After addition\n";
  for (int r = 0; r < 6; r += 1)
  { for (int c = 0; c < 4; c += 1)
      cout << " " << A[r][c];
    cout << "\n"; } }