One morning, Mari decided it was time for some exercise. She went over to her friend Timmy's house and together, they went out for a run. After a while, Mari quickened her pace to a sprint and pulled out her GPS. "I'm measuring how fast I am", she announced. Timmy kept pace, and soon they found themselves at a fork in the road. "I'm turning right," he declared. "No!" Mari cried back, but it was too late -- he had already turned. Mari resignedly followed him, lagging behind as she recovered from her sprint. Timmy turned around to see how far behind his friend was, and decided to let her catch up. "I'm running backwards," he called down, and soon they were side by side again. Timmy started to turn forwards again, but Mari stopped him. "I'm going backwards," she intoned, and spun around herself. The two ran backwards together for awhile. Eventually they turned forwards again, and continued their run as the path got steeper. As they slogged uphill, Timmy groaned, "I need someone to pull me." Spying an intersection ahead, he decided to get off the hill and told Mari, "I'm turning right here." As they rounded the corner, Mari suddenly rolled her ankle and crumpled to the ground. "I need a doctor!" she cried out. Timmy shook his head at the hyperbole and helped Mari to her feet, but after some walking, she decided to turn the next corner home. "I'm going right," she declared, and cut in front of Timmy onto the street. "Don't go in front of me," he cautioned, but Mari paid no heed. Crossly, he repeated, "Don't go in front of me!" Mari came to a halt and returned "I'm not moving. Feel free to go around me." Timmy sighed and sidestepped around her. The two continued home in silence.