오일러 1047

 

#1047 지능형 기차Ⅰ : 오일러OJ (euleroj.io)

max_people=0

cnt=0

people=[]

for i in range(0,8,2):

    x,y=map(int,input().split())

    people.append(x)

    people.append(y)

for i in range(0,8,2):

    cnt=cnt-people[i]

    cnt=cnt+people[i+1]

    if cnt>max_people:

        max_people=cnt

print(max_people)