There is a room with a height of 2.5 meters, the ground has an area of 4 X 2 meters. On one narrow side of the room there sits a fly centrally 20 centimeters below the ceiling, on the opposite wall there is the spider 60 centimeters above the floor (also centrally). Fly: "I am sure you are hungry and you want to eat me to have dinner!" Spider: "Yeah sure, I am very hungry and I can run 2 meters in one minute." The fly calculates a few seconds and says: "I am tired, I need a nap. I am gonna sleep now here exactly 3 minutes and then I fly away!!!" Will the spider have dinner, or has the fly calculated enough time to escape? Btw: The spider has to walk any time. No jumps, no drop, no tricks. The fly remains at its place 3 minutes sleeping.