// Count pairs (i, j) with i < j and A[i] + A[j] = target.

int PairSum(int[] A, int target) {
  int c = 0;
  int i = 0;
  while (i < A.length) {
    int j = i + 1;
    while (j < A.length) {
      if (A[i] + A[j] == target) { c = c + 1; };
      j = j + 1;
    };
    i = i + 1;
  };
  return c;
}