new_contents: def checkio(d):
      # get a list of coordinates
      d = [int(i) for i in d.replace('(','').replace(')','').split(',')]
      Ax, Ay = d[0:2]
      Bx, By = d[2:4]
      Cx, Cy = d[4:]
      
      # Avoid division by 0
      if Bx in [Ax, Cx]: Bx, Cx, By, Cy = Cx, Bx, Cy, By
      
      # Slope
      Ma = (By-Ay) / (Bx-Ax)
      Mb = (Cy-By) / (Cx-Bx)
      
      # Center coordinates
      Px = (Ma * Mb * (Ay-Cy) + Mb*(Ax+Bx) - Ma*(Bx+Cx)) / (2 * (Mb-Ma))
      
      # Avoid division by 0
      if Ma == 0.: 
          Py = ((Bx+Cx)/2 - Px)/Mb + (By+Cy)/2;
      else:
          Py = ((Ax+Bx)/2 - Px)/Ma + (Ay+By)/2
      
      radius = ((Px-Ax)**2 + (Py-Ay)**2)**.5
      
      C = [Px, Py, radius]
      for n in range(len(C)):
          C[n] = round(C[n], 2)
          if C[n] == int(C[n]):
              C[n] = int(C[n])
      
      return '(x-{})^2+(y-{})^2={}^2'.format(C[0], C[1], C[2])
  
subject: Create three-points-circle.py