Harsha runs his own company where people manufacture mobile devices.

Harsha is the owner of a mobile phone company and has 7 employees. Each employee wants to make their own mobile phone models. Each mobile phone model needs a certain number of screwdrivers to start their work. When the manufacturing process starts, the employees can pick up any arbitrary number of screwdrivers but not more than what they need.

For example - So if there are 3 employees and 6 six screwdrivers - 1st may capture 1 screwdriver, 2nd may capture 2 screwdrivers and 3rd might capture 3 screwdrivers. Alternatively, 1st might capture 2 screwdrivers, 2nd might capture 3 screwdrivers and 3rd might capture 1 screwdriver. Any such permutation is possible.

Once any employee completes making his mobile, he returns all screwdrivers that he has and these can then be picked up by remaining employees. If an employee is trying to make a mobile that needs X screwdrivers, then he will need exactly X screwdrivers at his disposal. If he doesn't have enough screwdriver, he will have to wait until some other employee completes making a phone and releases the screwdriver that they now possess. The number of screw drivers each employee (Total 7 employees) require for their mobile phones are 10, 20, 12, 7, 19, 7 and 17 respectively.

Harsha wants to know the minimum number of screw drivers so that regardless of the permutation of screwdrivers chosen by employees, everyone is able to make their mobile phone models.

Note: Every employee is selfish. There is no way to ensure cooperation between them as long as they haven't completed their work. They will simultaneously approach and try to get as many resources as possible.