#include <iostream>
#include <fstream>
#include <unordered_set>
using namespace std;
ifstream f("pairs.in");
ofstream g("pairs.out");
unordered_set<int> h;
unordered_set<int>::iterator it, jt;
int gcd(int a,int b)
{
    int r;
     while(b != 0)
        {
            r = a % b;
            a = b;
            b = r;
        }
        return a;
}
int n, a, k;
int main()
{
    f>>n;
    for(int i=0; i<n; ++i){
        f>>a;
        h.insert(a);
    }
    for(it=h.begin(); it!=h.end(); ++it){
            jt=it; ++jt;
    for(; jt!=h.end(); ++jt)
        if(gcd(*it, *jt)==1)
            ++k;//, cout<<*it<<' '<<*jt<<'\n';
    }
    g<<k;
    return 0;
}