pascal,sử dụng proceduce và function

const fi='prime.inp';
fo='prime.out';
var kt:array[0..9] of boolean;
s,s1:string[11];
n,i,tt,code,dem:integer;
f,g:text;
a:array[1..11] of integer;
function ngto(t:longint):boolean;
var i:longint;
check:boolean;
begin
check:=true;
for i:=2 to trunc(sqrt(t)) do
if(t mod i)=0 then 
begin 
check:=false; 
break; 
end;
if t<2 then 
check:=false;
ngto:=check;
end;
procedure nhap;
begin
readln(f,n);
for i:=1 to n do 
read(f,a[i]);
end;
procedure try(j:integer; s:string);
var i:integer;
begin
for i:=1 to n do
if (kt[i]) then begin
str(a[i],s1);
s:=s+s1;
val(s,tt,code);
if ngto(tt) then 
inc(dem);
kt[i]:=false;
if (length(s)<n) then 
try(j+1,s);
delete(s,length(s),1);
kt[i]:=true;
end;
end;
begin
assign(f,fi); reset(f);
assign(g,fo); rewrite(g);
nhap;
dem:=0;
s:='';
for i:=1 to n do 
kt[i]:=true;
try(1,s);
write(g,dem);
close(f);
close(g);
end.