#include<bits/stdc++.h>
#include <numeric>

using namespace std;

struct TwoSat {
    int n;
    std::vector<std::vector<int>> e;
    std::vector<bool> ans;
    TwoSat(int n) : n(n), e(2 * n), ans(n) {}
    void addClause(int u, bool f, int v, bool g) {
        e[2*u+f].push_back(2*v+g);
    }
    bool satisfiable() {
        std::vector<int> id(2 * n, -1), dfn(2 * n, -1), low(2 * n, -1);
        std::vector<int> stk;
        int now = 0, cnt = 0;
        std::function<void(int)> tarjan = [&](int u) {
            stk.push_back(u);
            dfn[u] = low[u] = now++;
            for (auto v : e[u]) {
                if (dfn[v] == -1) {
                    tarjan(v);
                    low[u] = std::min(low[u], low[v]);
                } else if (id[v] == -1) {
                    low[u] = std::min(low[u], dfn[v]);
                }
            }
            if (dfn[u] == low[u]) {
                int v;
                do {
                    v = stk.back();
                    stk.pop_back();
                    id[v] = cnt;
                } while (v != u);
                ++cnt;
            }
        };
        for (int i = 0; i < 2 * n; ++i) if (dfn[i] == -1) tarjan(i);
        for (int i = 0; i < n; ++i) {
            if (id[2 * i] == id[2 * i + 1]) return false;
            ans[i] = id[2 * i] > id[2 * i + 1];
        }
        return true;
    }
    std::vector<bool> answer() { return ans; }
};

void solve() {
	int n; cin >> n;
	vector<int>sz(7);
	for(int i = 0 ; i < 7 ; i ++) cin >> sz[i];

	int m = accumulate(begin(sz), end(sz), 0);
	TwoSat ts(m);

	for(int i = 1 ; i < 7 ; i ++) sz[i] += sz[i-1];

	auto id = [&](int day, int num) {
		if(day==0) return abs(num)-1;
		else return sz[day-1] + abs(num) - 1;
	};


	vector<bool>vis(2*m);
	for(int tt = 0 ; tt < n ; tt ++) {
		vector<int>vec(7);
		for(int i = 0 ; i < 7 ; i ++) cin >> vec[i];
		for(int i = 0 ; i < 7 ; i ++) {
			for(int j = i + 1 ; j < 7 ; j ++) {
				int u = id(i, vec[i]);
				int v = id(j, vec[j]);

				bool f1 = vec[i]>0;
				bool f2 = vec[j]>0;

				//if(u==19 and (v==21 or v==24)) {
				//	cout << u << ' ' << f1 << ' ' << v << ' ' << f2 << endl;
				//}

				ts.addClause(u, f1, v, !f2);
				ts.addClause(v, f2, u, !f1);

				vis[2*u+f1] = true;
				vis[2*v+f2] = true;
			}
		}
	}

	bool flag = true;
	for(int i = 0 ; i < 2*m ; i += 2) {
		flag &= !(vis[i] & vis[i+1]);
	}

	int v1, v2; cin >> v1 >> v2;

	int u1 = id(5, v1); bool f1 = v1>0;
	int u2 = id(6, v2); bool f2 = v2>0;

	if(flag and !vis[2*u1+f1]) {
		cout << "possible\n";
		return;
	}
	if(flag and !vis[2*u2+f2]) {
		cout << "possible\n";
		return;
	}

	ts.addClause(u1, !f1, u1, f1);
	ts.addClause(u2, !f2, u2, f2);

	//cout << u1 << ' ' << f1 << ' ' << u2 << ' ' << f2 << endl;

	if(ts.satisfiable()) {
		cout << "possible\n";
	}
	else{
		cout << "impossible\n";
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	solve();

	return 0;
}