Our jobs are to be done on four different machines. The cost in rupees of
 producing ith on the jth machine is given below. Assign the jobs to different machines
 so as to minimise the total cost.
 Jobs
 M1
 M2
 M3
 M4
 J1
 15
 11
 13
 15
 J2
 17
 12
 12
 13
 J3
 14
 15
 10
 14
 J4
 16
 13
 11
 17