# poly
# The poly tool returns the coefficients of a polynomial with the given sequence of roots.
# print numpy.poly([-1, 1, 1, 10])        #Output : [  1 -11   9  11 -10]

# roots
# The roots tool returns the roots of a polynomial with the given coefficients.
# print numpy.roots([1, 0, -1])           #Output : [-1.  1.]

# polyint
# The polyint tool returns an antiderivative (indefinite integral) of a polynomial.
# print numpy.polyint([1, 1, 1])          #Output : [ 0.33333333  0.5         1.          0.        ]

# polyder
# The polyder tool returns the derivative of the specified order of a polynomial.
# print numpy.polyder([1, 1, 1, 1])       #Output : [3 2 1]

# polyval
# The polyval tool evaluates the polynomial at specific value.
# print numpy.polyval([1, -2, 0, 2], 4)   #Output : 34

# polyfit
# The polyfit tool fits a polynomial of a specified order to a set of data using a least-squares approach.
# print numpy.polyfit([0,1,-1, 2, -2], [0,1,1, 4, 4], 2)
# #Output : [  1.00000000e+00   0.00000000e+00  -3.97205465e-16]

# Task :
# You are given the coefficients of a polynomial.
# Your task is to find the value of at point .

import numpy as np

P = list(map(float, input().split()))
P = np.array(P)
x = int(input())
print(np.polyval(P, x), end="")

# Sample Input
# 1.1 2 3
# 0

# Sample Output
# 3.0
