#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; ++i)
#define all(a) (a).begin(), (a).end()

int main() {
    cin.tie(nullptr);
    
    int N;
    cin >> N;

    vector<ll> res(N, 0);
    rep(num, 0, N) {
        string V;
        cin >> V;
        int siz = V.size();
        
        reverse(all(V));
        
        vector<ll> d(siz);
        rep(i, 0, siz) {
            if (V[i] - 'A' >= 0) d[i] = V[i] - 'A' + 10;
            else d[i] = V[i] - '0';
        }
        
        ll base = -1;
        rep(i, 0, siz) base = max(base, d[i]);
        base += 1;
        ll t = 1;
        rep(i, 0, siz) {
            res[num] += t * d[i];
            t *= base;
        }
    }
    
    sort(all(res));
    
    cout << res[0] << '\n';
}