A deranged illegal immigrant stabbed his upstairs neighbor 50 times inside their Long Island apartment building – all because her high heels made too much noise, prosecutors said Tuesday as he pleaded not guilty to slaughtering two women Rony Yahir Alvarenga Rivera, 22, allegedly told cops that he first hacked neighbor Eddy Raquel Hernandez Castillo to death on April 30 because the racket she made drove him nuts.