#include <iostream>
#include <fstream>

using namespace std;

ifstream in("pairs.in");
ofstream out("pairs.out");
int v[100001],i=1,j=1,m,p=0;

int pie(int a, int b){
    int r;
    while (b>0){
        r=a%b;
        a=b;
        b=r;
    }
    return a;
}

int main()
{
    in >> m;
    for(i=1;i<=m;i++)in >> v[i];
    for(i=1;i<=m;i++)
        for(j=1;j<=m;j++)
            if(v[i]!=v[j] && pie(v[i],v[j])==1 && i!=j)
                p++;
    cout << p/2;
}