Binary notation

You are given a non-negative integer $n$. Write it in binary — this is exactly how a computer stores numbers, with $0$s and $1$s. For example, $13 = 8 + 4 + 1 = 1101_2$.

A single integer $n$ ($0 \le n \le 10^{18}$).

The binary notation of $n$ without leading zeros. For $0$ — 0.

$n \bmod 2$ is the lowest bit and $n / 2$ is the rest. Repeat until $n$ becomes zero: the bits come out right to left, so print them in reverse order (or prepend them to a string).