In a certain code language, 'x' represents '+', '÷' represents 'x', '-' represents '÷' and '+' represents '-'. Find out the answer to the following question.
A man lifts a luggage of 25 kg from the ground and puts it on the head, 2.5 m above the ground. If the value of g = 10 m/s2, then the value of work done by him on the luggage is