a, b, c, d = map(int, input().split())
n = int(input())
mod = int(1e9+7)

x, y = -a, d
if n%8<=3: x = b
if 2<=n%8<=5: y = -c
if n%8 in (3,7): x = 0
if n%8 in (1,5): y = 0

ans = (x + y) * pow(2, (n+1)//2, mod) % mod
print(ans)