#include <bits/stdc++.h>
#define EB emplace_back
using std::cin;
using std::cout;

typedef std::vector <int> vector;
const int N = 11, N2 = 1025, INF = 0x3f3f3f3f;

int n, ALL;
int S[N];
int pos[N][N];
int lt[N][N], rt[N][N];
int f[N][N][N][N][N2];
vector hint[N];

inline void down(int &x, const int y) {x > y ? x = y : 0;}

inline int get_trans(int a, int b) {
	int i, u, v;
	if (S[b] & ~S[a]) return -1;
	u = hint[a].back();
	if (!~pos[b][u]) return hint[a].size();
	for (i = (int)hint[a].size() - 1; i > 0; --i) {
		v = u, u = hint[a][i - 1];
		if (!~pos[b][u] || pos[b][u] > pos[b][v]) break;
	}
	return i;
}

int main() {
	int i, j = 0, l, r, x, y, d, nl, nr, S, cur, ans = INF;
	std::ios::sync_with_stdio(false), cin.tie(NULL);
	memset(pos, -1, sizeof pos), memset(lt, -1, sizeof lt), memset(rt, -1, sizeof rt);
	cin >> n;
	for (i = 0; i < n; ++i)
		for (j = 0; cin >> x && x--; hint[i].EB(x)) ::S[i] |= 1 << x, pos[i][x] = j++;
	for (i = 0; i < n; ++i)
		for (j = 0; j < n; ++j)
			if (i != j) rt[i][j] = get_trans(i, j), lt[i][j] = get_trans(j, i);
	memset(f, 63, sizeof f), ALL = ~(-1 << n), f[n][0][n][0][0] = 0;
	for (i = 0; i < n; ++i) f[i][hint[i].size()][n][0][1 << i] = 0;
	for (S = 0; S <= ALL; ++S)
		for (i = 0; i <= n; ++i) for (l = (int)hint[i].size(); l >= 0; --l)
			for (j = 0; j <= n; ++j) for (r = 0; r <= (int)hint[j].size(); ++r)
				if ((cur = f[i][l][j][r][S]) < INF) {
					if (S == ALL && i == n && r == (int)hint[j].size()) down(ans, cur);
					for (x = 0; x < n; ++x) if (!(S >> x & 1)) {
						if (j == n || (~rt[j][x] && r >= rt[j][x])) down(f[i][l][x][0][S | 1 << x], cur);
						if (i != n && ~lt[i][x] && !l) for (y = lt[i][x]; y <= (int)hint[x].size(); ++y) down(f[x][y][j][r][S | 1 << x], cur);
					}
					if (i != n && !l) down(f[n][0][j][r][S], cur);
					for (d = 0; d < 9; ++d) {
						if (j == n) nr = r;
						else {
							if (!~pos[j][d] || pos[j][d] > r) continue;
							nr = r + (r == pos[j][d]);
						}
						if (i == n) nl = l;
						else {
							if (!l || !~pos[i][d] || pos[i][d] >= l) continue;
							nl = l - (l - 1 == pos[i][d]);
						}
						down(f[i][l][j][nr][S], cur + 1),
						down(f[i][nl][j][nr][S], cur + 1);
					}
				}
	cout << (ans >= INF ? -1 : ans) << '\n';
	return 0;
}