Задача: "Холмы"

lst = []
while (i := int(input())) != -1:
    lst.append(i)
 
print(sum(1 for i, e in enumerate(lst[1:-1], 1) if lst[i - 1] < e > lst[i + 1]))

arr = [None] * 3
counter = 0
for i in range(1000):
    arr[i%3] = int(input('->'))
    if arr[i%3] == -1:
        break
    if i > 1 and arr[(i-2)%3] < arr[(i-1)%3] > arr[i%3]:
        counter += 1
print(counter)

cur = prev = prev_prev = None
counter = 0
for i in range(1000):
    prev_prev = prev
    prev = cur
    cur = int(input('->'))
    if cur == -1:
        break
    if i > 1 and prev_prev < prev > cur:
        counter += 1
print(counter)

cur = prev = prev_prev = None
counter = 0
while True:
    prev_prev = prev
    prev = cur
    cur = int(input('->'))
    if cur == -1:
        break
    if None not in (prev_prev, prev) and prev_prev < prev > cur:
        counter += 1
print(counter)

cur = prev = prev_prev = None
counter = 0
for i in range(10**100):
    prev_prev = prev
    prev = cur
    cur = int(input('->'))
    if cur == -1:
        break
    if i > 1 and prev_prev < prev > cur:
        counter += 1
print(counter)

p = int(input())
c = int(input())
r = 0
flag = True
while flag:
    n = int(input())
    flag = n != -1
    if flag:
        if c>p and c>n:
            r += 1
        p, c = c, n
print(r)