a, b, n = map(int, raw_input().strip().split(' '))
binN = bin(n).lstrip('0b')
lenBinN = len(binN)
modulus = 10**9 + 7
listOfSuccSquares = [((a + b)/2)%modulus]
for i in xrange(lenBinN - 1):
    listOfSuccSquares.append((listOfSuccSquares[-1]**2)%modulus)
expValue = 1
for i in xrange(lenBinN):
    if binN[-(i + 1)] == '1':
        expValue = (expValue * listOfSuccSquares[i])%modulus
print expValue