NEED HELP IN ARRGRAPH

[cool123dude]

You are given a sequence of integers A1,A2,…,AN. You may change any number of its elements (possibly zero), obtaining a new sequence of positive integers B1,B2,…,BN. Each element of B must be an integer between 2 and 50 (both inclusive).

Let's define an undirected graph G with N vertices (numbered 1 through N). For each pair of different vertices i and j, there is an edge between i and j if and only if Bi and Bj are coprime.

You should choose the sequence B in such a way that G is a connected graph. The number of elements which need to be changed to obtain B from A should be minimum possible. Find one such sequence B and the minimum required number of changes.

It can be proven that a solution always exists — it is always possible to modify sequence A in such a way that G is connected.

Example Input
2
2
2 3
2
2 4
Example Output
0
2 3
1
2 3
Explanation
Example 1: There is an edge in G between vertices 1 and 2. This graph is connected, so there is no need to change any elements.

Example 2: There is no edge between vertices 1 and 2 since gcd(2,4)≠1. This graph is not connected. We can change element A2=4 to 3 and make this graph connected.

[cool123dude]

please give me some hint to solve this question

[helios]

Double-posting is not going to entice people to reply, just FYI.

http://www.cplusplus.com/forum/beginner/244493/