a,b,c = tuple(map(float,(input("Enter 3 sides of a triangle: ").split())))

V = sorted([a,b,c])
#if a+b<=c or a+c<=b or b+c<=a:
if V[0]+V[1] <= V[2]:
  print("Impossible triangle!")
else:
  if V[0]==V[2]:
    print("equilateral.  all 3 sides same")
  elif a==b or a==c or b==c:
      if V[0]**2 + V[1]**2 == V[2]**2:   #but can't input an irrational number?
          print("right isoceles. 2 sides same")
      else:
          print("isoceles. 2 sides same")
  elif V[0]**2 + V[1]**2 == V[2]**2:
    print("right scalene triangle")
  else:
    print("scalene. all 3 sides different")