const fs = require("fs");

const file = "inputs/2";
const fileContent = fs.readFileSync(file, "utf-8").trim();

const reports = fileContent.split("\n");

let safeCount = 0;

for (const element of reports) {
  const arr = element.trim().split(" ");
  const numbers = arr.map(Number);

  const isIncreasing = numbers.every(
    (num, i) => i === 0 || num > numbers[i - 1],
  );

  const isDecreasing = numbers.every(
    (num, i) => i === 0 || num < numbers[i - 1],
  );

  if (!(isIncreasing || isDecreasing)) {
    continue;
  }

  const isValidJumps = numbers.every(
    (num, i) => i === 0 || Math.abs(num - numbers[i - 1]) <= 3,
  );

  if (isValidJumps) {
    safeCount += 1;
  }
}

console.log(safeCount)