Java 算一算每行有幾個字

Word的定義是連續的字元（A~Z,a~z）所組成的字。
ASCII 字元表

輸入說明：
asd....asd
This is a book.

輸出說明：
2
4

import java.util.*;

public class HowManyWorld {
   public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String str;
      StringBuffer stb;
      int a,b;
      char c;
  
      while(sc.hasNext()){
         str = sc.nextLine();
         stb = new StringBuffer(str);
         a = 0;
         b = 0;
  
         for(int i = 0; i < str.length(); i++){
            c = stb.charAt(i);
            if( (c >= 65 && c <= 90) || (c >= 97 && c <= 122) ){
                b++;
                continue;
            }
            else if((b >= 1) && (i > 0 || c <= 64 || (c >= 91 && c <= 96) || c >= 123)){
                b = 0;
                a++;
            }
         }
         if( b >= 1 ){
            a++;
         }
         System.out.println(a);
      }
   }
}