#include <iostream.h>
#include <stdio.h>
FILE *f,*g;
int main()
{
long int m[1000],n,d,k,i,j;
int ok;
f=fopen("pairs.in","r");
fscanf(f,"%ld",&n);
for(i=0;i<n;i++)
	fscanf(f,"%ld",&m[i]);
fclose(f);
for(i=0;i<n-1;i++)
	for(j=i+1;j<n;j++)
		{ok=1;
		if(m[i]%2==0)  if(m[j]%2==0) ok=0;
		d=3;
		if(m[i]>m[j]){ while((ok==1) && (d<=m[j]))
				if(m[j]%d==0) {if(m[i]%d==0) ok=0;}
				     else d=d+2;
			     }
		       else  { while((ok==1) && (d<=m[i]))
				if(m[i]%d==0) {if(m[j]%d==0) ok=0;}
				     else d=d+2;
                             }
		if(ok==1) k++;
		}
g=fopen("pairs.out","w");
fprintf(g,"%ld",k);
fclose(g);
return 0;
}