#include<stdio.h>
int n,v[100000],sol;
int cmmdc(int a,int b)
{
	if(!b)return a;
	return cmmdc(b,a%b);
}
int main()
{
	FILE*f=fopen("pairs.in","r");
	fscanf(f,"%d",&n);
	int i=0,j;
	for(;i<n;++i)
	{
		fscanf(f,"%d",&v[i]);
		for(j=0;j<i;++j)
		if(cmmdc(v[j],v[i])>1)++sol;
	}
	fclose(f);
	FILE*g=fopen("pairs.out","w");
	fprintf(g,"%d\n",sol);
	fclose(g);
	return 0;
}