import java.io.*;
public class ChemApp
{
    public static void main(String []args) throws IOException{
        
        //Declare and creat array to store the names of the elements
        String[] name = {"","hydrogen","helium","lithium","beryllium","boron","carbon"};
        
        //Declare and creat array to store the symbols for the elements
        String[] symbol = {"","H","He","Li","Be","B","C"};
        
        //Declare and creat array to store average molar masses for the elements
        double[] mass = {0.0,1.01, 4.00, 6.94, 9.01, 10.81, 12.01};
        
        //Define input variable to read from keyboard
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        
        //Define variable to store index provided by user
        int input;
        
        //Prompt user for an index number
        System.out.println("Please input element number: ");
        input = Integer.parseInt(in.readLine());
        
        //Display the result
        System.out.println();
        System.out.println("Element number " + input + " is " + 
                           name[input] + " (symbol = " + symbol[input] + 
                           ") with average molar mass of " + 
                           mass[input] + " g/mol.");
            
        
}           
       }