출처 | https://www.acmicpc.net/problem/5073

코드

while(1):
    arr = sorted(list(map(int,input().split())))
    if arr[0] == arr[1] == arr[2] == 0:
        break
    if arr[0] + arr[1] <= arr[2]:
        print("Invalid")
    
    elif arr[0] == arr[1] == arr[2]:
        print("Equilateral ") 
    
    elif arr[0] == arr[1] or arr[1] == arr[2] or arr[0] == arr[2]:
        print("Isosceles")
    
    else:
        print("Scalene")