def p2a(p, m1, m2):
    """
    It computes the separation (Rsun) given m1 (Msun), m2 (Msun) and p (days).
    """        
    yeardy=365.24
    AURsun=214.95
    p = p/yeardy
    a = AURsun*(p*p*(m1 + m2))**(1./3.)
    return a