First number = {firstNumber}.
First cost = {firstCost}.
Rest cost = {restCost}.
Max cost = {maxCost}.
Magic number calculation is ceil( (Max cost - First number * (First cost - Rest cost) ) / Rest cost )
The magic number for this project is {number}.
It is calculated as ceil( (118 - 2*(9-3)) / 3 ) or ceil( (118 - 12)/3 ) or ceil (106/3).
The answer should be 36 since 106/3 = 35.33333.
Why does the calculation come to ceil(-35.3333) which is -35?