A certain restaurant operates $7$ days a week. Waiters are hired to work $6$ hours per day. The union contract specifies that each waiter must work $5$ consecutive days and then have $2$ consecutive days off. All waiters receive the same weekly salary. Staffing requirements are shown in the following table.

$\backslash$table$[[$Day$,$Required number of waiter hours$],[$Monday$,150],[$Tuesday$,200],[$Wednesday$,400],[$Thursday$,300],[$Friday$,700],[$Saturday$,800],[$Sunday$,300]]$

The manager wishes to find an employment schedule thatisfies these requirements at minimum cost. Formulate an appropriate mathematical model.