#include <cstdint>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
using namespace std;

int N;
vector<string> V;
vector<int64_t> VV;

void input(istream& in)
{
	in >> N;
	V.resize(N);
	for (int i = 0; i < N; i++) {
		in >> V[i];
	}
}

int64_t resolve()
{
	VV.reserve(N);
	for (string& s : V) {
		int base = 2;
		for (char ch : s) {
			if (ch > base) {
				base = ch;
			}
		}
		base = (base < 'A') ? (base - '0') : (base - 'A' + 10);
		base++;
		int64_t value = 0;
		for (char ch : s) {
			value *= base;
			value += (ch < 'A') ? (ch - '0') : (ch - 'A' + 10);
		}
		VV.push_back(value);
	}
	int64_t value = *min_element(VV.begin(), VV.end());
	return value;
}

int main()
{
	input(cin);
	cout << resolve() << endl;
	return 0;
}