"""Advent day 1, challenge 2

Count the number of times the input number
is higher than the previous one, but do a 3 day sliding window
"""

depths = []

with open("1_1_input.txt") as f:
    depths = [int(line) for line in f.readlines()]

sliding_sums = [sum(depths[i:i+3]) for i in range(len(depths) - 2)]

prev_depth = None
n_increased = 0
for depth in sliding_sums:
    if (prev_depth is not None
            and depth > prev_depth):
        n_increased += 1

    prev_depth = depth

print(n_increased)