Boris and Stella are walking on a circular path which has a radius of 1000 meters. They start walking at the same time. Boris starts at the northernmost point of the path, and Stella starts at the easternmost point. Boris walks clockwise. Stella walks counterclock- wise, and she walks three times as fast as Boris walks. They pass each other for the first time after 300 seconds. How far (in a straight line) is Boris from his staring point when he has been running for 1500 seconds?