programming Q MOCK TEST

Question

Consider the following program along with push and pop operations on stack which can contain atmost 

The decimal value equivalent to the binary number printed by above code is _______

Comments

this is made easy Q exactly  same ( i just copy and paste )

i m not getting answer  

i need your help in this q

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what is the input

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how they have given answer 57, no input is given for the question.