// https://projecteuler.net/problem=1

/* Multiples of 3 and 5

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below the provided parameter value number.

*/

const multiplesThreeAndFive = (num) => {

if (num < 1) throw new Error('No natural numbers exist below 1')

let total = 0

// total for calculating the sum

for (let i = 1; i < num; i++) {

if (i % 3 === 0 || i % 5 === 0) {

total += i

}

}

return total

}

export { multiplesThreeAndFive }