#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define RREP(i,s,e) for (i = e-1; i >= s; i--)
#define rrep(i,n) RREP(i,0,n)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 1e8

typedef long long ll;

ll power(ll a, int n) {
    if (a == 0)
        return 1;
    else
        return a * power(a,n-1);
}

int main() {
    int i, j, n;
    ll ans;
    cin >> n;
    ans = power(36,12);
    rep (i,n) {
        int base, w;
        ll x, v;
        string s;
        cin >> s;
        w = s.size();
        base = 0;
        for (char c : s) {
            if (isdigit(c))
                base = max(base,c - '0');
            else
                base = max(base,c - 'A' + 10);
        }
        base++;
        v = 0;
        rep (j,w){
            if (isdigit(s[w-j-1]))
                x = s[w-j-1] - '0';
            else
                x = s[w-j-1] - 'A' + 10;
            v += power(base,j)*x;
        }
        ans = min(ans,v);
    }
    cout << ans << endl;
    return 0;
}