programming problem regarding room capacity

Write at least 5 sentences stating your reason that the programming problem regarding room capacity should incorporate a condition to be able to obtain the required output. If you think that this problem will be solved without a condition, kindly write the equivalent source code.

Below is the sample run for the said programming problem:
Enter room capacity: 45
Enter actual class size: 40
Available seat/s: 5
Excess head count: 0

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Enter room capacity: 40
Enter actual class size: 45
Available seat/s: 0
Excess head count: 5