Java - ArrayOutOfBoundsException help me
===

import java.util.*;

import java.util.Arrays;

public class ScoreCalc {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		char[] alphabet = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
		int[] score = {1,3,3,2,1,4,2,4,1,8,5,1,3,1,1,3,10,1,1,1,1,4,4,8,4,10};
		System.out.println("Enter word: ");
		String word = in.nextLine();
		int totalScore = 0;
		char[] wordArray = word.toCharArray();
		for(int i=0; i<wordArray.length; i++)
		{
			System.out.println(wordArray[i]);
			int index = Arrays.asList(alphabet).indexOf(wordArray[i]);
			System.out.println(index);
			totalScore = totalScore + score[index];
		}
		System.out.println(totalScore);
	}
}

This keeps coming up with Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1

Because it can't find any of the characters in the array alphabet can someone help plz!