#define _CRT_SECURE_NO_WARNINGS
#include <queue>
#include <set>
#include <map>
#include <list>
#include <stack>
#include <cmath>
#include <functional>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iterator>
#include <algorithm>
#include <iostream>

#define aLL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define F(i,j,k) fill(i[0],i[0]+j*j,k)
#define P(p) cout<<(p)<<endl;
#define EXISt(s,e) ((s).find(e)!=(s).end())
#define INF 1<<25
#define MAX 100000000
#define PI 3.14159265258979
#define pb push_back
#define mp make_pair
using namespace std;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<double> vd;
typedef pair<int, int> pii;
typedef pair<long, long> pll;
typedef long long ll;
int dx[] = { 0,1,0,-1 };
int dy[] = { -1,0,1,0 };

struct edge{ int to,cost; };

ll to10(int dec, string num) {
	ll a = 0,b = 1;
	for (int i = num.length() - 1; i >= 0; i--) {
		if ('A' <= num[i] && num[i] <= 'Z') {
			a += b*(10 + (num[i] - 'A'));
		}
		else {
			a += b*(num[i] - '0');
		}
		b *= dec;
	}
	return a;
}

int sttoi(std::string str) { 
	int ret; 
	std::stringstream ss; ss << str;
	ss >> ret; 
	return ret; 
}
bool sort_greater(const pair<string, int> &a, const pair<string, int> &b) {
	return a.second > b.second;
}

ll combination(ll n, ll k) {
	ll ans = 1;
	for (ll i = 0; i < k; i++)ans *= n - i;
	for (ll i = 0; i < k; i++)ans /= k - i;
	return ans;
}

void solve() {
	int n;
	cin >> n;
	ll mini = 8000000000000000000;
	rep(i, n) {
		string s;
		cin >> s;
		int maxi = -1;
		for (int j = 0; j < s.length(); j++) {
			if ('A' <= s[j] && s[j] <= 'Z') {
				maxi = max(maxi, 10 + (s[j] - 'A'));
			}
			else {
				maxi = max(maxi, s[j] - '0');
			}
		}
		mini = min(mini, to10(maxi + 1, s));
	}
	cout << setprecision(20) << mini << endl;
}

int main() {
	solve();
	return 0;
}