#include <bits/stdc++.h>

#define rep(i, n) for (int (i) = 0; (i) < (int)(n); (i)++)

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;
typedef unsigned long long ull;

ull get(const string& s) {
    int ma = 0;
    int n = s.size();
    for (int i = 0; i < n; i++) {
        if ('0' <= s[i] && s[i] <= '9') {
            ma = max(ma, (int)(s[i] - '0'));
        } else {
            ma = max(ma, (int)(s[i] - 'A') + 10);
        }
    }
    ma++;
    ull cur = 1;
    ull ret = 0;
    for (int i = n-1; i >= 0; i--) {
        if ('0' <= s[i] && s[i] <= '9') {
            ret += (s[i]-'0') * cur;
        } else {
            ret += (s[i]-'A'+10) * cur;
        }
        cur *= ma;
    }
    return ret;
}

int main() {
    int N;
    cin >> N;
    ull ans = 1ll<<63;
    for (int i = 0; i < N; i++) {
        string s;
        cin >> s;
        ans = min(get(s), ans);
    }
    cout << ans << endl;
    return 0;
}