Error: Could not find or load main class inputprogram

How to fix this error?
 

import java.util.Scanner;

class inputprogram {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.println(“Enter your first name: “);
        string firstname = input.next();

        System.out.println(“Enter your last name: “);
        string lastname = input.next();

        System.out.println(“Your full name is “+firstname+” “+lastname);
    }  
}