#include<iostream>
#include<fstream>
using namespace std;
ifstream f("pairs.in");
ofstream g("pairs.out");
long long n, a[101], x, y,i, c,j,s,v[101],viz[101];
int prim(long n, long m)
{
    while (m != 0)
    {
        int r = n % m;
        n = m;
        m = r;
    }
    return n;
}
int main()
{
    f >> n;
    for (i = 1; i <= n; i++)
        f >> a[i];
    for(i=1; i<n; i++)
        for(j=i+1; j<=n; j++)
            if(i!=j && prim(a[i],a[j])==1)
                s++;
  g<<s;
}