#include<stdio.h>
int cmmdc(int a, int b){
	if(a%b==0)
		return b;
	return cmmdc(b,a%b);
}
int main(){
	int n,m[100000],i,j,k=0;
	freopen("pairs.in","r",stdin);
	freopen("pairs.out","w",stdout);
	scanf("%d",&n);
	for(i=0;i<n;i++)
		scanf("%d",&m[i]);
	for(i=0;i<n;i++)
		for(j=0;j<n;j++)
			if((m[i]!=m[j])&&(cmmdc(m[i],m[j])==1))
				k++;
	printf("%d",k/2);
	fclose(stdin);
	fclose(stdout);
	return 0;
}