from pandas import read_table


def read_header(filename):
    with open(filename, "r") as f:
        header = f.readline().split()
    return int(header[0])


def parse_file(filename):
    n = read_header(filename)
    m = 50
    df = read_table(
        filename, names=["source", "destination", "distance"], sep=" ", skiprows=[0]
    )
    return n, m, df