What is mistake ????

Question

https://code.sololearn.com/cZEybNKMl6Cy/?ref=app

Answer 1

Nothing..

Answer 2

I guess you have to separate inputs with spaces or newlines. Eg:
5+7
might get consumed by the first nextInt() and produces an error because of the plus sign. When
5 + 7
or
5
+
7
will work.