Two students stayed on the 100th floor of a skyscraper. One day, the lift was out of order. They agreed to climb up in a happy mood, just like picnicking and mountaineering.
In the beginning, they joked and laughed along the staircases. However, they started to pant like a dog on the sixtieth floor. On the ninetieth floor, they almost collapsed on the floor.
After so much hardship, they finally reached their unit. Thinking that they could relax, they fumbled in their pocket for the key to the door but found none. They forgot to get the key from the janitor on the first floor...