Write a program to input a String and print the Number of Alphabets in it.

import java.util.*;
public class Num_Alpha
{
    public static void main()
    {
        Scanner sc = new Scanner(System.in);
        String s;
        char ch;
        int c=0, i, l;
        System.out.println("Enter a string:");
        s = sc.nextLine();
        l = s.length();
        for(i=0;i<l;i++)
        {
            ch = s.charAt(i);
            if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z'))
            c=c+1;
        }
        System.out.println("The number of alphabets are: "+c);
    }
}