Нахождение наибольшего общего делителя

function Nod(a,b:integer):integer;{определение НОД двух чисел}
begin
while a<>b do
if a>b then a:=a-b else b:=b-a;
Nod:=a;
end;

uses crt;
var a,b,d:word;
function NOD(m,n:integer):integer;
begin
while m<>n do
if m>n then m:=m-n else n:=n-m;
NOD:=m;
end;
begin
clrscr;
write('a=');readln(a);
write('b=');readln(b);
writeln;
writeln('NOD(a,b)=',NOD(a,b));
readln
end.

for i:=1 to N do begin
if ((a div i) = 0) and ((b div i) = 0) then 
max:=i;
end;
write(max);

for i:=10 to 99 do begin
if ((i div 3) = 0) or ((i div 5) = 0) do 
writeln(i);
end;

program test;
uses crt;
var a,b,i,nol,men,bol:integer;
begin
clrscr;
write('vvedite n: ');readln(a);
write('vvedite tsifri');
men:=0;bol:=0;nol:=0;
for i:=1 to a do
begin
clrscr;
write('vvedite tsifru ',i,': ');readln(b);
if b<0 then men:=men+1;
if b>0 then bol:=bol+1;
if b=0 then nol:=nol+1;
end;
writeln('menishe 0: ',men);
writeln('bolishe 0: ',bol);
writeln('ravno 0: ',nol);
readln;
end.

uses crt;
Var Mas:array [1..100] of integer;
    n,i,k,c:integer;
begin
clrscr;
 Writeln (' Vvedite kol-vo celyx chisel ');
 Readln (n);
 for i:=1 to n do begin write ('Vvedite ',i, ' chislo ');
                        Readln (mas[i]);
                  end;
 Writeln (' Vvedennye chisla ');
 for i:=1 to n do write (mas[i]:4);
 Writeln;
 For i:=1 to n do
  if mas[i]<0 then k:=k+1;
 for i:=1 to n do
  if mas[i]=0 then c:=c+1;
Writeln ('Kol-vo chisel <0 =',k);
Writeln ('Kol-vo chisel = 0 =',c);
Readln
end.