using System;
using System.Collections;
using System.Collections.Generic;
using System.Numerics;

class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		
		Dictionary<char,int> D=new Dictionary<char,int>();
		for(char x='0';x<='9';x++)D[x]=(int)(x-'0');
		for(char x='A';x<='Z';x++)D[x]=10+(int)(x-'A');
		for(int i=0;i<N;i++){
		}
		
		
		BigInteger Min=0;
		for(int i=0;i<N;i++){
			char c='.';
			for(int j=0;j<S[i].Length;j++){
				c=(char)Math.Max((int)c,(int)S[i][j]);
			}
			BigInteger B=D[c]+1;
			
			BigInteger bb=1;
			BigInteger bi=0;
			for(int j=S[i].Length-1;j>=0;j--){
				bi+=bb*D[S[i][j]];
				bb*=B;
			}
			if(i==0)Min=bi;
			Min=Min>bi?bi:Min;
		}
		
		Console.WriteLine(Min);
		
	}
	int N;
	String[] S;
	public Sol(){
		N=ri();
		S=new String[N];
		for(int i=0;i<N;i++)S[i]=rs();
	}




	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(){return Console.ReadLine().Split(' ');}
	static int[] ria(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>int.Parse(e));}
	static long[] rla(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>long.Parse(e));}
	static double[] rda(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>double.Parse(e));}
}