def fast_power(a,n):
    """
    This function assumes that n >= 0
    """
    result = 1
    value = a
    power = n
    while power > 0:
        if power & 0x1:
            result = result * value
            result = result % 1000000007
        value = value * value
        value = value % 1000000007
        power = power//2
    return result

data = map(int, raw_input().split(' '))

a = data[0]
b = data[1]
t = data[2]

answer = fast_power((a+b)/2, t)
print int(answer)