Answer:
Your program would run without error if you declared the first and second string variables before using them:
Modify the following:
first=input.nextLine();
second=input.nextLine();
to:
String first=input.nextLine();
String second=input.nextLine();
Explanation:
Required
Program to print two strings in forward and reversed order
The program you added is correct. The only thing that needs to be done is variable declarations (because variables that are not declared cannot be used).
So, you need to declared first and second as strings. This can be done as follows:
(1) Only declaration
String first, second;
(2) Declaration and inputs
String first=input.nextLine();
String second=input.nextLine();