#include <iostream>
#include<string>
#include<algorithm>

using namespace std;

int main() {
	int N;
	cin >> N;
	
	long long ans = (long long)5e18;
	for (int i = 0; i < N; i++)
	{
		string s;
		cin >> s;

		int d = 2;
		for (int j = 0; j < s.size(); j++)
		{
			if (s[j] >= '0' && s[j] <= '9') d = max(d, s[j] - '0' + 1);
			else d = max(d, s[j] - 'A' + 11);
		}


		long long temp = 0;
		long long mul = 1;
		for (int j = s.size() - 1; j >= 0; j--)
		{
			int num;
			if (s[j] >= '0' && s[j] <= '9') num = s[j] - '0';
			else num = s[j] - 'A' + 10;

			temp += num * mul;
			mul *= d;
		}

		ans = min(ans, temp);
	}

	cout << ans;
}