my solution is the following:
start with least common multiple = 1
make char array of 1000 000 to track forbidden divisors

let div be the divisor and ans the answer

if ans == 1 make new lcm of the previous lcm and current divisor. if it is over 10^12 - fail. find all the divisors of div, check that they are not forbidden in the forbidden array
if ans == 0 - check if lcm is divisible by the divisor and fail if it is.

complexitiy O(n * sqrt(1000000)) (sqrt from the "find all divisors)

my solution gets 0.5 sec (using cin,cout with tie(null))
what is the solution that gets less than 0.1 sec? Is there any hint?