Write  if the following code fragment doesn't compile. Write if the code fragment's execution causes undefined behavior at run-time. Otherwise, write the exact value printed to standard output by the code fragment.

int b[][3] = {5, 3, 9, 4, 1, 2, 6, 7, 8}, m = 0;
for (int k = 0; k < 3; ++k) {
  int j = 0;
  for (int i = k; i >= 0; i--) {
    m += b[i][j++];
  }
}
printf("%d", m);