input: Write a function to calculate the distance between two points given their coordinates (x1, y1) and (x2, y2). Use the Euclidean distance formula to compute the distance. If the inputs are invalid or not provided correctly, return -1.
  assert distance_between_points(2, 7, 4, 9)==2.8284271247461903
  assert distance_between_points(0, 0, 3, 4)==5.0
  assert distance_between_points(1, 2, 5, 5)==5.0
  assert distance_between_points(-1, -1, 1, 1)==2.8284271247461903
  assert distance_between_points(0, 0, 0, 0)==0.0
output: def distance_between_points(x1, y1, x2, y2):
      if not (isinstance(x1, (int, float)) and isinstance(y1, (int, float)) and isinstance(x2, (int, float)) and isinstance(y2, (int, float))):
          return -1
      return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5