from math import pi, sqrt, sin, cos

def ad_term(k, x, i):
    return (-1)**i * pi * (k + sqrt(abs(x))) / (2*abs(x))

def ad_sum5(k, a):
    x1 = a    
    x2 = ad_term(k, x1, 2)
    x3 = ad_term(k, x2, 3)
    x4 = ad_term(k, x3, 4)    
    x5 = ad_term(k, x4, 5)
    
    #print(x1, x2, x3, x4 x5)
    
    return round(x1+x2+x3+x4+x5, 4)