Nhập 1 mảng số nguyên dương

Nhập mảng phải có nhập số lượng phần tử nữa bạn nhé.

program hotrotinhoc;

const fi='bai5.inp';

fo='bai5.out';

var f: text;

i,j,n,max,max1,max2,max3,max4: longint;

a: array[1..32000] of integer;

function dn(x: integer): integer;

var s: integer;

begin

s:=0; dn:=0;

while x<>0 do

begin

s:=s*10+(x mod 10);

x:=x div 10;

end;

dn:=s;

end;

function nt(x1: integer): boolean;

var j: integer;

begin

nt:=false;

if x1<2 then exit;

for j:=2 to trunc(sqrt(x1)) do

if x1 mod j=0 then exit;

nt:=true;

end;

function tongcs(x2: integer): integer;

var s1: integer;

begin

s1:=0;

while x2<>0 do

begin

s1:=s1+(x2 mod 10);

x2:=x2 div 10;

end;

tongcs:=s1;

end;

function ucln(x3,y: integer) : integer;

var z: integer;

begin

while y<>0 do

begin

z:=x3 mod y;

x3:=y;

y:=z;

end;

ucln:=x3;

end;

procedure ip;

begin

assign(f,fi);

reset(f);

readln(f,n);

for i:=1 to n do

read(f,a[i]);

close(f);

end;

procedure out;

begin

assign(f,fo);

rewrite(f);

max:=0; max2:=0; max3:=0;

for i:=1 to n do

begin

if (dn(a[i])=a[i]) and (a[i]>max) then max:=a[i];

if dn(a[i])>max2 then max2:=dn(a[i]);

if (nt(a[i])) and (tongcs(a[i])>max3) then max3:=a[i];

end;

writeln(f,max);

for i:=1 to n do if dn(a[i])=max2 then

writeln(f,a[i]);

max4:=0;

for i:=1 to n do

for j:=i to n do

if (a[i]<>a[j]) and (ucln(a[i],a[j])>max4) then max4:=ucln(a[i],a[j]);

for i:=1 to n do

for j:=i to n do

if ucln(a[i],a[j])=max4 then writeln(f,a[i],' ',a[j]);

write(f,max3);

close(f);

end;

begin

ip;

out;

end.