#P1136. Three Capitals

    ID: 137 远端评测题 2000ms 128MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>湖南省第十二届大学生计算机程序设计竞赛(HNCPC2016)

Three Capitals

Description

In ICPCCamp, there are only three capitals – Alpha, Beta and Gamma. There are also a bidirectional roads between capitals Alpha and Beta, b roads between Alpha and Gamma, and c roads between Beta and Gamma.

Bobo lives in capital Alpha and would like to travel around ICPCCamp. He will start from capital Alpha, travel along each road exactly once, and return back to capital Alpha. It is clear that Bobo has many plans to choose from. He would like to find out the number of different plans, modulo (109 + 7). Note that two plans A and B are considered different only if there exists an i where the i-th traveled road in plan A is different from the i-th road in plan B.

Input

The input contains at most 30 sets. For each set:

The first line contains 3 integers a, b, c(1 ≤ a, b, c ≤ 105).

Output

For each set, an integer denotes the number of different ways modulo (109 + 7).

1 1 3
1 3 1
100000 100000 100000
12
24
525502296