g.py

import argparse
import itertools as it


def pipe(x, fn):
    for f in fn:
        x = f(x)
    return x


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("n", type=int)
    args = parser.parse_args()

    pipe(it.count(1), [
        lambda x: map(lambda y: str(y).count("1"), x),
        it.accumulate,
        lambda x: enumerate(x, 1),
        lambda x: filter(lambda y: y[0] == y[1], x),
        lambda x: it.islice(x, args.n),
        list,
        reversed,
        next,
        iter,
        next,
        print,
    ])


if __name__ == "__main__":
    main()