"use strict";
let fs = require("fs");
let rounds = parseInt(fs.readFileSync("./rounds.txt", "utf8"));
let x = 1.0;
let pi = 1.0;
for (let i = 2; i < rounds + 2; i++) {
x *= -1;
pi += x / (2 * i - 1);
}
pi *= 4;
console.log(pi);
