#include <iostream>
#include<string>
#include<algorithm>
using namespace std;
typedef unsigned long long ULL;
int main() {
	int n; cin >> n;

	ULL ans = 1ULL << 63;
	for (int i = 0; i < n; i++){
		string s; cin >> s;

		int d = 2;
		for (int j = 0; j < s.size(); j++){
			if (isalpha(s[j])) s[j] = s[j] - 'A' + 10;
			else s[j] -= '0';
			d = max(d, (int)s[j]);
		}
		d++;

		ULL num = 0, mul = 1;
		for (int j = s.size() - 1; j >= 0; j--, mul *= d){
			num += s[j] * mul;
		}
		ans = min(ans, num);
	}
	printf("%llu\n", ans);
	return 0;
}