Availability

There are $N$ cricketers in an academy. Each player practices for some time in the nets $($only $1$ net is present$).$

To solve the time collision issue, the coach is using a calender application. Now there is one new addition in the academy. Given the practice slots of $N$ cricketers, give all suggestions of the time frame available for practice.

Note : $($The net is available all day,with practice hours described as $0-1000000000)$

Task