#include <iostream>
using namespace std;

//useful to avoid name colloisions
namespace foo{
	int value() {return 5;}
}

namespace bar{
	const double pi = 3.1416;
	double value() {return pi*2;}
}

int main()
{
	int x = 10;
	int y = 20;
	{
		int x;	// ok, inner scope
		x = 50;	// sets value to inner x
		y = 50;	// sets value to outer y

		cout<<"inner-block\n";
		cout<<"x : "<<x<<"\n";
		cout<<"y : "<<y<<"\n";
	}

	cout<<"outer-block\n";
	cout<<"x : "<<x<<"\n";
	cout<<"y : "<<y<<"\n";

	cout<<foo::value() << "\n";
	cout<<bar::value() << "\n";

	cout<<bar::pi << "\n";
	
	return 0;
}