C++ :

#include<iostream>
using namespace std;
int main()
{
	int a,b;
	cin>>a>>b;
	for (int i=1; i<=a&&i<=b; i++)
		if (a%i==0 && b%i==0)
			cout<<i<<endl;
	return 0;
}

Pascal :

program p2691(input,output);
var
  n,m,i,x:longint;
begin
  readln(n,m);
  for i:=1 to n do
    begin
      if (n mod i=0) and (m mod i=0) then
        writeln(i);
    end;
end.

Java :

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner in=new Scanner(System.in);
        while(in.hasNext()){
            int a=in.nextInt();
            int b=in.nextInt();
            int min=0;
            if(a>b){
                min=b;
            }
            else{
                min=a;
            }
            for(int i=1;i<=min;i++){
                if(a%i==0&&b%i==0){
                    System.out.println(i);
                }
            }
        }
    }
}