03. Combinations

function combinations(input) {
    let num = parseInt(input[0]);
    let counter = 0;
    for (let a = 0; a <= num; a++) {
        for (let b = 0; b <= num; b++) {
            for (let c = 0; c <= num; c++) {
                if (a + b + c === num){
                    counter++;
                }
            }
        }
    }
    console.log(counter);
}