1. 백준 - 삼각형과 세 변
while True:
    a, b, c = list(map(int, input().split()))
    if a == b == c == 0:
        break
    elif a == b == c:
        print("Equilateral")
    elif max(a, b, c) >= a + b + c - max(a, b, c): 
        print("Invalid")
    elif (a == b) or (a == c) or (b == c):
        print("Isosceles")
    else:
        print("Scalene")
        
    
2. 백준 - 가희와 키워드
import sys
sys.stdin = open('input.txt', 'r')
N, M = map(int, sys.stdin.readline().split())
keyword = {sys.stdin.readline().rstrip() : 0 for _ in range(N)}
answer = N
for i in range(M):
    essay = list(sys.stdin.readline().rstrip().split(","))
    for j in essay:
        if j in keyword.keys():
            if keyword[j] == 0:
                answer -= 1
                keyword[j] = 1
    print(answer)
3. 백준 - 카드 2
from collections import deque
N = int(input())
lst = deque(range(1, N+1))
while len(lst) != 1:
    lst.popleft()
    a = lst.popleft()
    lst.append(a)
    
print(*lst)
4. 프로그래머스 - 카펫
def solution(brown, yellow):
    answer = []
    sol = brown - 4 
    n1 = 1 
    while True:
        n2 = (sol - 2*n1) // 2 
        if n1*n2 != yellow: 
            n1 += 1
        else:
            answer = [max(n1, n2)+2, min(n1, n2)+2]
            break
    return answer