def f(n):
    if (n == 0):
        return f0
    elif (n == 1):
        return f1
    else:
        return 3 * f(n-1) + 2 * f(n-2) + 2 * g(n-1) + 3 * g(n-2)

def g(n):
    if (n == 0):
        return g0
    elif (n == 1):
        return g1
    else:
        return g(n-1) + 2*g(n-2)



f1, f0, g1, g0 = map(int, raw_input().strip().split(" "))
n = int(raw_input())

print f(n)