#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

string V[1000];

bool cmpr(string a, string b)
{
    return a.size() < b.size();
}

long long f1(string a)
{
    int b;

    char maxc = 0;
    for (int i = 0; i < a.size(); ++i) maxc = max(maxc, a[i]);

    b = (isdigit(maxc) ? maxc - '0' + 1 : maxc - 'A' + 11);

    ll c = 1;
    ll res = 0;

    for (int i = a.size() - 1; i >= 0; --i) {
        res += (isdigit(a[i]) ? a[i] - '0' : a[i] - 'A' + 10) * c;
        c *= b;
    }

    return res;
}

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

    for (int i = 0; i < N; ++i) cin >> V[i];

    ll mi = LLONG_MAX;

    for (int i = 0; i < N; ++i) mi = min(mi, f1(V[i]));

    cout << mi << endl;
}