#include <bits/stdc++.h>
using namespace std;
long long a[20],i,j,dem;
bool kt;
int main()
{
for (i=1; i<=20; i++) cin>>a[i];
dem=0;
for (i=1; i<=20; i++)
if (a[i]>1)
{
kt=true;
for (j=2; j<=sqrt(a[i]); j++)
if (a[i]%j==0) kt=false;
if (kt==true) dem++;
}
cout<<dem;
return 0;
}
uses crt;
var
n,i,dem:integer;
a:array[1..20] of integer;
function ngto(n:integer):boolean;
var i:integer; ok:boolean;
begin
if n<2 then ok:=false;
for i:=2 to trunc(sqrt(n)) do
if n mod i=0 then ok:=false else ok:=true;
ngto:=ok;
end;
begin
clrscr;
write('nhap so phan tu cua day: '); readln(n);
for i:=1 to n do
begin
write('nhap phan tu thu [',i,']= ]); readln(a[i]);
end;
dem:=0;
for i:=1 to n do
if ngto(a[i]) then inc(dem);
write("trong day co ',dem,' phan tu la so nguyen to');
readln
end.