C++ :

#include<bits/stdc++.h>
using namespace std;
int a,b;
int main()
{
	for(int i=3;i<=100;i++)
	{
		if(i%3==0||i%5==0)
		{
			cout<<i<<endl;
		}
	}
	return 0;
}

Pascal :

var a:longint;
begin
  for a:=1 to 100 do
  if (a mod 3=0) or (a mod 5=0) then writeln(a);
end.