空调

差分：

N = int(input())
p = list(map(int, input().split()))
t = list(map(int, input().split()))
d,s=[0]*100010,[0]*100010
for i in range(N):
    d[i] = p[i]-t[i]

for i in range(N):
    s[i] += d[i]
    s[i+1] -= d[i]
ans = 0
for i in range(N+1):
    if s[i]>0:
        ans += s[i]
print(ans)