Why wont Java accept the input integer?

Question

import java.util.Scanner;

public class Main {

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
double pi = 3.14;
//your code goes here
int r = input.nextInt();
double p = 2 * pi * r;
System.out.println(p);
}
}

This is one of the beginner problems and if I define r as the 'sample number' it works for that single instance, but the program wants to input other ones.
My issue is that i cant seem to get it to communicate with my code to add its own inputs.
Any help would be much appreciated!
Best

Answer 1

scanner.nextInt()
//not input

Answer 2

Hima Thank you!