Score : $300$ points
There are $N$ integers, $A_1, A_2, ..., A_N$, written on the blackboard.
You will choose one of them and replace it with an integer of your choice between $1$ and $10^9$ (inclusive), possibly the same as the integer originally written.
Find the maximum possible greatest common divisor of the $N$ integers on the blackboard after your move.
Input is given from Standard Input in the following format:
$N$ $A_1$ $A_2$ $...$ $A_N$
Print the maximum possible greatest common divisor of the $N$ integers on the blackboard after your move.
3 7 6 8
2
If we replace $7$ with $4$, the greatest common divisor of the three integers on the blackboard will be $2$, which is the maximum possible value.
3 12 15 18
6
2 1000000000 1000000000
1000000000
We can replace an integer with itself.