08. Condense Array to Number

function solve(arr) {

    for (let i = 0; i < arr.length - 1; i++) {
        for (let j = 0; j < arr.length - 1; j++) {
            arr[j] += arr[j + 1];
        }
        arr.pop();
        i--;
    }
    console.log(arr[0]);
}