100 atcoder#ABC125C. [ABC125C] GCD on Blackboard

[ABC125C] GCD on Blackboard

Score : 300300 points

Problem Statement

There are NN integers, A1,A2,...,ANA_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 11 and 10910^9 (inclusive), possibly the same as the integer originally written.

Find the maximum possible greatest common divisor of the NN integers on the blackboard after your move.

Constraints

  • All values in input are integers.
  • 2N1052 \leq N \leq 10^5
  • 1Ai1091 \leq A_i \leq 10^9

Output

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the maximum possible greatest common divisor of the NN integers on the blackboard after your move.

3
7 6 8
2

If we replace 77 with 44, the greatest common divisor of the three integers on the blackboard will be 22, which is the maximum possible value.

3
12 15 18
6
2
1000000000 1000000000
1000000000

We can replace an integer with itself.