#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <climits>

using namespace std;

int getDigit(char c) {
	return isupper(c) ? c - 'A' + 10 : c - '0';
}

int main() {
	int n;
	string v;

	cin >> n;
	long long ans = LONG_LONG_MAX;
	for (int i = 0; i < n; i++) {
		cin >> v;

		int maxi = 0;
		for (int j = 0; j < v.size(); j++) {
			maxi = max(maxi, getDigit(v[j]));
		}

		int sinsu = maxi + 1;
		long long x = 1;
		long long val = 0;
		for (int k = 0; k < v.size(); k++) {
			val += x * getDigit(v[v.size() - k - 1]);
			x *= sinsu;
		}

		ans = min(val, ans);
	}

	cout << ans << endl;
	return 0;
}