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NASA experiment
      NASA wants to conduct some experiments in a new space shuttle. There
are N possible experiments and M possible equipment. The cost to bring
equipment i is Ci. The benefit of experiment j is Bj. Each experiment need 
a specified set of equipments. Please find out a list of equipment which 
will yield maximum benefit.

For example
Number of experiments : 3
Number of pieces of equipment  : 5
The cost to bring each equipment : 2 3 4 100 3

Benefit of experiment 1 : 5
The equipment needed by experiment 1 :  1 2 3

Benefit of experiment 2 : 100
The equipments needed by experiment 2 : 1 2

Benefit of experiment 3 : 3
The equipment needed by experiment 3 : 1 2 4 5

Solution :
Bring equipment : 1 2 3
Conduct experiment : 1 2
Maximum Benefit = 5 + 100 - 2 - 3 - 4

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