TASK

Problem

#11

Given radius `r`, use π = 3.14 and print circumference `2πr`.

EXAMPLE

Example

Input

5

Output

31.400000000000002

LIMITS

Constraints

All numeric input values fit in JavaScript `Number`.

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LEARN Theory for this problem

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### Circumference

JavaScript arithmetic works with numeric values stored in variables. A clear solution reads the needed values, computes the formula with `+`, `-`, `*`, `/` or `**`, and prints only the final result.

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NEED HELP? Hints

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['Write the formula using named intermediate values if it contains more than one operation.', 'Before printing, output only the computed result and do not add explanatory text that is absent from the required format.']

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ANSWER Solution

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const fs = require('fs');
const input = fs.readFileSync(0, 'utf8').trimEnd();
let r = Number(input);
let result = (((2) * (3.14)) * (r));
console.log(Object.is(result, 0) ? '0.0' : result);