#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>


using namespace std;


using ull = unsigned long long;
using ll = long long;
using ld = long double;


#define all(v) v.begin(), v.end()
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep2(i, n, m) for (ll i = n; i <= m; ++i)
#define rep3(i, n, m) for (ll i = n; i >= m; --i)


template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
template<class T> using pq  = priority_queue<T>;


template<class S, class T> inline bool chmax(S &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class S, class T> inline bool chmin(S &a, T b) { if (a > b) { a = b; return true; } return false; }


int main() {
  int n;
  cin >> n;

  ll ans = 5e18;

  while (n--) {
    string s;
    cin >> s;

    char mx = 0;
    rep(i, s.size()) mx = max(mx, s[i]);

    ll w = (isalpha(mx) ? mx - 'A' + 11 : mx - '0' + 1);
    ll weight = 1;
    reverse(all(s));

    ll val = 0;
    rep(i, s.size()) {
      ll d;
      if (isalpha(s[i])) d = s[i] - 'A' + 10;
      else d = s[i] - '0';

      val += weight * d;
      weight *= w;
    }

    chmin(ans, val);
  }

  cout << ans << endl;
  return 0;
}