def calc(a, b, n):
    """
    x_n を計算する
    """
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        ret_i = 0
        ret_i1 = 1
        for i in range(n - 1):
            swap = a * ret_i1 + b * ret_i
            ret_i = ret_i1 
            ret_i1 = swap % (10 ** 9 + 7)
        return ret_i1

if __name__ == "__main__":
    input_line = input().split(" ")
    print(calc(int(input_line[0]), int(input_line[1]), int(input_line[2])))