import java.io.File;
import java.util.Scanner;
import java.util.Arrays;
public class BeautifulStrings
{
	public static int totalBeauty(String line)
	{
		//build alphabet/freq/val triplets
		String[][] alphabet_freq = { {"a", "0"},
									{"b", "0"},
									{"c", "0"},
									{"d", "0"},
									{"e", "0"},
									{"f", "0"},
									{"g", "0"},
									{"h", "0"},
									{"i", "0"},
									{"j", "0"},
									{"k", "0"},
									{"l", "0"},
									{"m", "0"},
									{"n", "0"},
									{"o", "0"},
									{"p", "0"},
									{"q", "0"},
									{"r", "0"},
									{"s", "0"},
									{"t", "0"},
									{"u", "0"},
									{"v", "0"},
									{"w", "0"},
									{"x", "0"},
									{"y", "0"},
									{"z", "0"} };
		line = line.toLowerCase();
		StringBuffer buff = new StringBuffer(line);
		final int BASE_ALPHA = 97;
		//97 - 122 (int) char
		for (int i = 0; i < buff.length(); i++)
		{
			char temp = buff.charAt(i);
			int tempnum = (int) temp;
			int setfreq = tempnum-BASE_ALPHA;
			if (tempnum >= 97 && tempnum <= 122)
			{
				for (int j = i; j < buff.length(); j++)
				{
					char tempother = buff.charAt(j);
					if (tempother == temp)
					{
						buff.replace(j,j+1," ");
						//add to freq array
						int tempArrayValue = Integer.parseInt(alphabet_freq[setfreq][1]);
						tempArrayValue += 1;
						alphabet_freq[setfreq][1] = Integer.toString(tempArrayValue);
					}
				}
			}
			else
			{
				continue;
			}
		}
		//initialize from 26-1 if whole alphabet is represented
		boolean end = false;
		int k = 0;
		int total = 0;
		int first = 26;
		int currentLargestPlace = 0;
		int currentLargestFreq = 0;
		while (end == false)
		{
			//debug
			//System.out.println(Arrays.toString(alphabet_freq[k]));
			int thisFreq = Integer.parseInt(alphabet_freq[k][1]);
			if (thisFreq > currentLargestFreq)
			{
				//System.out.println("First if block");
				currentLargestFreq = thisFreq;
				currentLargestPlace = k;
			}
			//when reach end, first check if 0
			if (k == 25)
			{
				//System.out.println("Second if block");
				if (currentLargestFreq == 0) 
				{
					//System.out.println("Embedded if block");
					end = true;
					break;
				}
				total += currentLargestFreq * first;
				//System.out.println("Current total = " + total);
				first -= 1;
				currentLargestFreq = 0;
				alphabet_freq[currentLargestPlace][1] = "0";
				k = 0;
			}
			else
			{
				k++;
			}
		}
		return total;
	}
	public static void main(String[] args)
	{
		try
		{
			File file = new File(args[0]);
			Scanner scanner = new Scanner(file);
			while(scanner.hasNextLine())
			{
				System.out.println(totalBeauty(scanner.nextLine()));
			}
		}
		catch (Exception e)
		{
			System.out.println(e);
		}
	}
}