Doubt: ADAGCD(Ada and GCD) on Spoj

Problem Link: Spoj problem

Code:https://ideone.com/2afY09

Approach: finding all the possible prime factors of the 1st number, and storing them in a map(map1) and for subsequent numbers inserting them into another map(map2) and then later comparing them to map1 if map2 doesn't have map1 values than it cannot be in a gcd while if they are present then minimum of map1 and map2 values.

For example (sample input):

3

4 1 2 3 4

1 36

2 6 5

after 1st iteration:

map1[ 2 ] = 3

map1[3] = 1

after 2nd iteration:

map1[ 2 ] = 2

map1[3] = 1

after 3rd iteration:

map1[ 2 ] = 1

map1[3] = 1

and multiplying them in the last. pow(2,1)*pow(3,1) = 6 (answer)

Result: TLE

How can I optimize my code or please suggest a better algorithm to solve this problem?

Thanks in advance!