Random step problem

a.js

l = (N) => {
    sum = 0, iter = 1000000;
    for (let i = 1; i < iter; i++) {
        var s = 0,
            j = 0;
        while (s < N) {
            s += Math.random();
            j++;
        }
        sum += j;
    }
    console.log(sum / iter)
};