#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;




int main() {
map<char,int>z;
for(int i=0;i<10;i++)
{char v='0'+i;z[v]=i;} 
for(int i=0;i<26;i++)
{char v='A'+i;z[v]=i+10;} 
int n;
cin>>n;
vector<string>p;
for(int i=0;i<n;i++){
	string t;
	cin>>t;
	p.push_back(t);

}

unsigned long long int r=9999999999999999999;
for(int i=0;i<n;i++){
	int b=2;
	for(int j=0;j<p[i].size();j++){
		b=max(b,z[p[i][j]]+1);
	}
unsigned long long int f=0;
	for(int j=0;j<p[i].size();j++){
		f*=b;
		f+=z[p[i][j]];
	}
	r=min(r,f);
}
cout<<r<<endl;

	return 0;
}