How to make this more time efficient??

Question

#include <iostream>
#include<math.h>
using namespace std;
int lcm(int a,int b)
{
for(int i=max(a,b) ; ;i++)
{
if(i%a==0 && i%b==0)
return i;
}
}

int main() {
// your code goes here

int n;
cin>>n;
int a[n];
for(int i=0 ;i<n ;i++)
cin>>a[i];

int maxa=0;

for(int i= 0 ; i<n ;i++)
{
for(int j=i+1 ;j<n ;j++)
{
maxa=max(maxa,lcm(a[i],a[j]));
}
}

cout<<maxa;
return 0;
}

Answer 1

I hv used the nested loop to make all posssible pairs from the array

Answer 2

Nooo , the task is to make pairs from the array and find the maximum lcm from it

Answer 3

Sorry i could not upload the question .
But thanks for the response☺