# Baekjoon-14719-빗물

20 Sep 2022참고: https://namhandong.tistory.com/139

```
H,W = map(int, input().split(' '))
blocks = list(map(int, input().split(' ')))
max_idx, max_h = 0,0
for idx, h in enumerate(blocks):
if h > max_h:
max_h = h
max_idx = idx
total = 0
# from left
h_t = 0
for w in range(max_idx):
h = blocks[w]
total += max(h_t-h,0)
if h_t < h:
h_t = h
# from right
h_t = 0
for w in range(W-1,max_idx,-1):
h = blocks[w]
total += max(h_t-h,0)
if h_t < h:
h_t = h
print(total)
```