# Michael Cusack
# U2-1

s1 = raw_input("Length of first side: ")
s2 = raw_input("Length of second side: ")
s3 = raw_input("Lenght of third side: ")

s = [s1, s2, s3,]
s.sort()
l = s[2]
if l < (s[0] + s[1]):
	if s1 != s2 and s1 != s3 and s2 != s3:
		print "The triangle is scalene."
	elif s1 == s2 and s2 == s3:
		print "The triangle is equilateral."
	elif s1 == s2 or s1 == s3 or s2 == s3:
		print "The triangle is isosceles."
else:
	print "The triangle cannot exist with given sides."