line = [int(i) for i in input().strip().split(' ')]
a = line[0]
b = line[1]
t = line[2]

expected_growth = (a + b) / 2
expected_size = 1

for i in range(t):
    expected_size = (expected_size * expected_growth) % (10 ** 9 + 7)

print (str(int(expected_size)))