from math import atan 
from math import pi 
from math import cos 
from math import sin 
 
def findAngle(x, y): 
    #Finds the angle a point makes with the x-axis, working in degrees 
    if x > 0 and y == 0: 
        return 0 
    if x < 0 and y == 0: 
        return pi 
    if x == 0 and y > 0: 
        return pi / 2 
    if x == 0 and y < 0: 
        return 3 * pi / 2 
    if x > 0 and y > 0: 
        return (atan(y/(x+0.0))) 
    if x < 0 and y > 0: 
        return pi + (atan(y/(x+0.0))) 
    if x < 0 and y < 0: 
        return pi + (atan(y/(x+0.0))) 
    if x > 0 and y < 0: 
        return 2 * pi + (atan(y/(x+0.0))) 
 
def findArg(x, y, m, n): 
    angle = findAngle(x, y) 
    if m % 2 == n % 2: 
        return angle 
    else: 
        return (7/12.0 * pi - angle) % (2*pi) 
 
i, k, q = map(int, input().split(' ')) 
a_i, b_i = map(float, input().split(' ')) 

 
length = ((a_i)**2 + (b_i)**2)**0.5 
angle = findArg(a_i, b_i, i, k)
ak = cos(angle) * length
bk = sin(angle) * length 
print(2**(2*(k-i) - q) * (ak+bk))