def main():

    a, b, n = map(int, input().split())
    X = [0] * (n + 1)
    X[0], X[1] = 0, 1
    for i in range(n - 1):
        X[i + 2] = (a * X[i + 1] + b * X[i]) % (10 ** 9 + 7)

    print(X[n])

if __name__ == "__main__":
    main()