#!/usr/bin/env python3
from typing import List

class Solution:
    def __init__(self) -> None:
        self.lines: List[str] = []
        self.lines_split: List[List[str]] = []
        self.lines_clean: List[List[int]] = []
        self.result: int = 0

    def read(self) -> None:
        with open("input") as f:
            self.lines = f.readlines()

    def clean(self) -> None:
        for i in range(len(self.lines)):
            self.lines[i] = self.lines[i].strip()

    def split_lines(self) -> None:
        for i in range(len(self.lines)):
            self.lines_split.append(self.lines[i].split())

    def clean_lines(self) -> None:
        for j in range(len(self.lines_split)):
            tmp_list: List[int] = []
            for i in range(len(self.lines_split[j])):
                tmp_list.append(int(self.lines_split[j][i]))
            self.lines_clean.append(tmp_list)

    # This currently is an ugly hack. HACK: Make this look nicer.
    def _is_safe(self, levels: List[int]) -> bool:
        rate = None
        for i in range(len(levels) - 1):
            if rate == None:
                rate = 0

            difference: int = levels[i] - levels[i+1]

            if rate == 0:
                if difference < 0:
                    rate = -1
                elif difference > 0:
                    rate = 1
            elif rate == 1:
                if difference < 0:
                    return False
            elif rate == -1:
                if difference > 0:
                    return False

        for i in range(len(levels) - 1):
            rate: int = 0
            difference: int = abs(levels[i+1] - levels[i])
            if difference not in range(1,4):
                return False
        return True

    def calculate_result(self) -> int:
        for level in self.lines_clean:
            if self._is_safe(level):
                self.result += 1
        return self.result


def main() -> None:
    solver: Solution = Solution()
    solver.read()
    solver.clean()
    solver.split_lines()
    solver.clean_lines()
    result: int = solver.calculate_result()
    print(f"The amount of safe values is: {result}")

if __name__ == "__main__":
    main()