IBMOA #1
Drawing Edges
估计简单可在线判题
考点(AI 标注)位运算
n labeled vertices form an undirected simple graph with no self-loops and no multiple edges; the graph may be disconnected. Find the number of distinct graphs modulo 1000000007.
输入格式
One line containing n. On this site 1≤n≤10^9.
输出格式
Output one integer, the answer.
样例 1
输入:
4
输出:
64
样例 2
输入:
1
输出:
1
样例 3
输入:
3
输出:
8
样例说明
The examples give 64, 1 and 8 respectively; with one vertex, only the edgeless graph exists.