#include <bits/stdc++.h>

using namespace std;

ifstream f("pairs.in");
ofstream g("pairs.out");

int n,a[100005],nr;

int cmmdc(int n, int m)
{
    while ( m )
    {
        int r=n%m;
        n=m;
        m=r;
    }
    return n;
}

int main()
{
    f >> n;
    for (int i=1; i<=n; i++ )
        f >> a[i];
    sort(a+1,a+n+1);
    for (int i=1; i<n; i++ )
        for (int j=i+1; j<=n; j++ )
           if ( cmmdc(a[i],a[j])==1 )
              nr++;
    g << nr;
    return 0;
}