정수 삼각형

p. 376

 

n=int(input())
d=[]
for i in range(n):
  d.append(list(map(int, input().split())))

for i in range(1,n):
  for j in range(len(d[i])):

    # 왼쪽
    if j == 0:
      left=0
    else:
      left=d[i-1][j-1]

    # 오른쪽
    if j==i:
      right=0
    else:
      right=d[i-1][j]
    
    d[i][j]=d[i][j]+max(left, right)


print(max(d[n-1]))