uses crt;
 var a : array[1..100] of integer ;
  n,i : integer; 
   P : real ;
   begin
    clrscr;
write('N=');
 readln(n);
 p := 1 ;
for i := 1 to n do
     begin
    write('a[',i,']=');
    readln(a[i]);
    if a[i] mod 3 = 0 
        then p := p * a[i];
     end ;
    writeln('Tong=',p:0:2);
     end.

uses crt;

var a: array[1..100] of integer;

i,n,s: integer;

begin

clrscr;

write ('nhap n: ');  readln (N);

s:=1;

for i:=1 to n do

begin

write ('nhap pt thu ',i,': ');  readln (a[i]);

if a[i] mod 3=0 then s:=s*a[i];

end;

writeln ('Tich la: ',s);

readln;

end.

$#Trumtinhoc$