def magnitud_semblant(d, est, eps):
    l = []
    magn = d[est][0]
    for k, v in d.items():
        magn2 = v[0]
        if k != est and abs(magn2-magn) < eps:
            l.append(k)
    l.sort()
    return l

def mes_propera_de_magnitud(d, magn, eps):
    s = ''
    for k, v in d.items():
        magn2, dist2 = v
        if abs(magn2-magn) < eps:
            if s == '':
                s = k
                dist = dist2
            elif dist2 < dist:
                s = k
                dist = dist2
    return s