a,b,t = map(int, input().strip().split(" "))

def power(x, y) :
    if (y == 0):
        return 1
    temp = power(x, y//2)
    if(y%2 ==0):
        return temp * temp
    else :
        return x * temp * temp

print(int(power(0.5 * (a+b), t) % 1000000007))