P20154 [CodeChef] PRIMEGRAPH
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题目描述

While doing his research in the Institute of Lovely Graphs, Rashad came up with another problem called Prime Graph.

Prime Graph is a simple graph (undirected graph which does not contain any self-loops or multiple-edges) with N nodes such that the degree of each node is prime. Rashad wants to know what is the maximum number of edges a prime graph with N nodes can contain. Can you help Rashad answer this question?

Note: The degree of a node in a simple graph is the number of edges that are incident on the node and a prime number is a natural number greater than 1 which has exactly two divisors - 1 and the number itself.

------ Input Format ------

  • The first line contains T - the number of test cases. Then the test cases follow.
  • The first line of each test case contains N - the number of nodes in the graph.

------ Output Format ------

For each test case, output the maximum number of edges a prime graph of N nodes can contain.

------ Constraints ------

$1 ≤ T ≤ 100$
$3 ≤ N ≤ 10^{5}$

----- Sample Input 1 ------
3
3
4
5
----- Sample Output 1 ------
3
6
7

----- explanation 1 ------
- For $N = 3$ and $4$ we can construct a complete graph (a graph in which every pair of distinct vertices is connected by an edge).
- For $N = 5$ we can construct a prime graph with at most $7$ edges. One such graph is:

输入格式

见题面

输出格式

见题面

样例输入
3 3 4 5
样例输出
3 6 7