var a = "global a";
var b = "global b";
var c = "global c";
var d = "global d";
{
  var a = "outer a";
  var b = "outer b";
  d = "outer d";
  {
    var a = "inner a";
    d = "inner d";
    print a;
    print b;
    print c;
    print d;
  }
  print a;
  print b;
  print c;
  print d;
}
print a;
print b;
print c;
print d;