An open window 40 feet above the ground level-Riddle

Two world's famous prisoners 'Dhamaka Singh' and 'Jagga' are locked in a cell. They plan to escape from the cell. They noticed there is an open window 40 feet above the ground level. Both of them tried very hard but are never able to reach there. Then both of them decided to plan to escape by a tunnel and they start digging out. After digging for just 5 days, Dhamaka Singh and Jagga come out with a much easier plan of tunnelling and they escaped.