P5019 [NOIP2018 提高组] 铺设道路 - 洛谷 | 计算机科学教育新生态 (luogu.com.cn)

n = int(input())
data = list(map(int,input().split()))ans = 0
for i in range(1,n):if data[i]>data[i-1]:ans += data[i]-data[i-1]print(ans+data[0])