A program reads data from a text file and stores it in a stack. The stack Stack is stored as a 1D array of up to 20 elements. The pointer TopOfStack stores the index of the last element stored in the stack. The values stored in the stack are used to perform mathematical operations. A total is initialised to the first value in the stack. The first value in the stack will always be a number. The next value will be a mathematical operator and the next value will be the number to apply to the calculation. This is repeated until there are no values left in the stack. There will always be a number following a mathematical operator. For example, the contents of a stack are:

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