#include <stdio.h>
bool e[1000005];
int main()
{
	int i,j,a,b,r,d=0,n;
	FILE *f1,*f2;
	f1=fopen("pairs.in","r");
	f2=fopen("pairs.out","w");
	fscanf(f1,"%d",&n);
	for(i=1;i<=n;i++)
	{
		fscanf(f1,"%d",&a);
		e[a]=true;
	}
	for(i=1;i<=1000004;i++)
		if(e[i])
			for(j=i+1;j<=1000004;j++)
				if(e[j])
				{
					a=i;
					b=j;
					while(b)
					{
						r=a%b;
						a=b;
						b=r;
					}
					if(a==1)	d++;
				}
	fprintf(f2,"%d",d);
	fclose(f1);
	fclose(f2);

	return 0;
}