import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;


public class Porto {

	Scanner in = new Scanner(System.in); 
	Map<Character, Integer> swaps = new HashMap<Character, Integer>();
	List<String> wordsList = new ArrayList<String>();
	List<Character> letterList = new ArrayList<Character>();
	Set<Character> firsts = new HashSet<Character>();
	double totalTries =0; 
	
	public static void main(String[] args){
		new Porto().go();
	}

	public void go(){

		int n = in.nextInt();
		in.nextLine();
		String[] words = new String[n];
		for (int i=0; i<n; i++){
			words[i] = in.nextLine();
			wordsList.add(words[i]);
			firsts.add(words[i].charAt(0));
		}
		makeLetterList();
		totalTries = Math.pow(10, letterList.size());
		int solutions = tryAll();
		System.out.println(solutions);

		
	}

	
	public int tryAll(){
		int total=0; 
		for (int i=0; i<totalTries; i++){
			String s = makeStringFromNum(i);
			if (checkDups(s)){continue;}
			if (!makeMap(s)){continue;}
			if (checkSum()){total++;}
			System.out.println(total);
			
		}
		return total; 
		
	}
	
	public boolean checkSum(){
		List<Integer> attempts = new ArrayList<Integer>();
		
		for (int i=0; i<wordsList.size(); i++){
			attempts.add(transform(wordsList.get(i)));
		}
		int sum =0;
		for (int i=0; i<attempts.size()-1; i++){
			sum+=attempts.get(i);
		}
		if (sum==attempts.get(attempts.size()-1)){
			return true;
		}
	
		return false;
	}
	
	public int transform(String s){
		int t = 1; 
		int number = 0;
		for (int i=s.length()-1; i>=0; i--){
			int digit = swaps.get(s.charAt(i));
			number+= t*digit; 
			t*=10; 
		}
		return number;
	}
	
	public boolean checkDups(String s){
		boolean[] checks = new boolean[10];
		
		for (int i=0; i<s.length(); i++){
			int num = Integer.parseInt(String.valueOf(s.charAt(i)));
			if (checks[num]){return true;}
			checks[num]=true;
		
		}
		return false;
		
	}
	
	public String makeStringFromNum(int i){
		String s = String.valueOf(i);
		while (s.length()!=letterList.size()){
			s = "0" + s;
		}
		return s; 
	}
	
	
	public boolean makeMap(String s){
		for (int i=0; i<letterList.size(); i++){
			char c = letterList.get(i);
			int num = Integer.parseInt(String.valueOf(s.charAt(i)));
			if (firsts.contains(c) && num==0){return false;}
			swaps.put(c, num);
		}
		return true;
	}
	
	public void makeLetterList(){
		for (int i=0; i<wordsList.size(); i++){
			for (int j=0; j<wordsList.get(i).length(); j++){
				swaps.put(wordsList.get(i).charAt(j), 0);
				if (!letterList.contains(wordsList.get(i).charAt(j))){
					letterList.add(wordsList.get(i).charAt(j));
				}
			}
		}
	}
	
	public boolean checkFirst(char c){
		for (int i=0; i<wordsList.size(); i++){
			if (wordsList.get(i).charAt(0)==c){
				return true;
			}
		}
		return false; 
	}
	


}