#include <bits/stdc++.h>
using namespace std;

int n;
vector<int> words;
vector<int> wlen;

int main() {
	ios::sync_with_stdio(0), cin.tie(0);
	cin >> n;
	words.resize(n);
	wlen.resize(n);
	for (int i = 0; i < n; i++) {
		string s;
		cin >> s;
		int cur = 0;
		wlen[i] = int(s.size());
		for (int j = 0; j < wlen[i]; j++) {
			cur = 2 * cur + int(s[j] - '0');
		}
		words[i] = cur;
	}
	priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;
	vector<vector<int> > dist(n);
	for (int i = 0; i < n; i++) {
		dist[i].assign(wlen[i]+1, -1);
		dist[i][wlen[i]] = wlen[i];
		pq.push(make_pair(wlen[i], i * 20 + wlen[i]));
	}
	while (!pq.empty()) {
		int d = pq.top().first;
		int cur = pq.top().second;
		int i = cur / 20;
		int r = cur % 20;
		pq.pop();
		if (r == 0) {
			cout << d << '\n';
			exit(0);
		}
		if (dist[i][r] < d) continue;
		int suffix = words[i] & ((1 << r) - 1);
		for (int j = 0; j < n; j++) {
			if (i == j && r == wlen[j]) continue;
			int newi = -1, newr = -1, extra = 0;
			if (wlen[j] <= r) {
				if ((suffix >> (r - wlen[j])) == words[j]) {
					newi = i;
					newr = r - wlen[j];
					extra = 0;
				}
			} else {
				if (suffix == (words[j] >> (wlen[j] - r))) {
					newi = j;
					newr = wlen[j] - r;
					extra = newr;
				}
			}
			if (newi == -1) continue;
			int newd = d + extra;
			if (dist[newi][newr] == -1 || dist[newi][newr] > newd) {
				dist[newi][newr] = newd;
				pq.push(make_pair(newd, newi * 20 + newr));
			}
		}
	}
	cout << 0 << '\n';
}