#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;
using ull = unsigned long long;

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

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;

	ll res{ (ll)1e20 };
	for (int i = 0; i < n; ++i)
	{
		string s;
		cin >> s;
		string sw(s);
		sort(sw.rbegin(), sw.rend());
		char m = sw[0];
		char r = (m <= '9' ? '0' : 'A' - 10);
		int mm = m - r + 1;

		ll x = 1, sum{ 0 };
		for (int d = (int)s.size() - 1; d >= 0; --d)
		{
			if (s[d] <= '9')
				sum += (s[d] - '0') * x;
			else
				sum += (s[d] - 'A' + 10) * x;
			x *= mm;
		}
		chmin(res, sum);
	}

    cout << res << "\n";

	return 0;
}