"""
3*pi + SUM[n=0; n=INF]{(-1)^(n+1)*6*(x/2)^(2*n+1) / (2*n+1)}

"""

from math import *

x = float(input('x = '))
eps = float(input('eps = '))

### Sn = 6*(x/2)
Sn = 0 ###
S = 3*pi
### n= 1
n=0 ###


while True:
    ### Sn = pow(-1, (n+1))*pow(Sn, (2*n+1)) / (2*n+1)
    Sn = pow(-1, (n+1))*6*pow((x/2), (2*n + 1)) / (2*n+1)###
    S += Sn
    n += 1
    if fabs(Sn) < eps:
        break

### zn = 6*atan(x/2)
zn = 6*(pi/2-atan(x/2)) ###
print('{0} {1:.4f}'.format('6*arcctg(x/2)= ', zn))
print('{0} {1:.4f}'.format('S = ', S))