#include <iostream>
#include <fstream>
using namespace std;
int n,nr=0,a,b,v[100000];
int main()
{
    ifstream f("pairs.in");
    ofstream g("pairs.out");
    f>>n;
    for (int i=1;i<=n;i++)
    {
        f>>v[i];
    }
    for (int i=1;i<=n-1;i++)
    {
        for (int j=i+1;j<=n;j++)
        {
            if ((v[i]-v[j]==1) or (v[j]-v[i]==1)) nr++;
            else if ((v[i]%v[j]!=0) and (v[j]%v[i]!=0))
            {
                a=v[i];
                b=v[j];
                while (a!=b)
                {
                    if (a<b) b=b-a;
                    else a=a-b;
                }
                if (a==1) nr++;
            }
        }
    }
    g<nr;
    return 0;
}