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

using i64 = long long;

struct TwoSat {
    int n;
    vector<vector<int>> g;
    vector<int> ans;
    TwoSat(int n) : n(n), g(2 * n), ans(n) {}
    void add(int u, bool x) {
        g[2 * u + !x].push_back(2 * u + x);
    }
    void add(int u, bool x, int v, bool y) {
        g[2 * u + !x].push_back(2 * v + y);
        g[2 * v + !y].push_back(2 * u + x);
    }
    bool satisfiable() {
        vector<int> where(2 * n, -1), dfn(2 * n, -1), low(2 * n, -1), stk;
        auto dfs = [&](auto dfs, int u) -> void {
            static int T = 0, cnt = 0;
            dfn[u] = low[u] = T++;
            stk.push_back(u);
            for (auto v : g[u]) {
                if (dfn[v] == -1) {
                    dfs(dfs, v);
                    low[u] = min(low[u], low[v]);
                } else if (where[v] == -1) {
                    low[u] = min(low[u], dfn[v]);
                }
            }
            if (dfn[u] == low[u]) {
                int v;
                do {
                    v = stk.back();
                    where[v] = cnt;
                    stk.pop_back();
                } while (u != v);
                cnt++;
            }
        };
        for (int i = 0; i < 2 * n; i++)
            if (dfn[i] == -1)
                dfs(dfs, i);
        for (int i = 0; i < n; i++) {
            if (where[2 * i] == where[2 * i + 1]) {
                ans.clear();
                return false;
            }
            ans[i] = where[2 * i] > where[2 * i + 1];
        }
        return true;
    }
};

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    auto solve = [&]() {
        int n;
        cin >> n;

        vector<int> c(7);
        for (int i = 0; i < 7; i++) {
            cin >> c[i];
        }

        int N = 0;
        vector<vector<int>> id(7);

        for (int i = 0; i < 7; i++) {
            id[i].resize(c[i]);
            for (int j = 0; j < c[i]; j++) {
                id[i][j] = N++;
            }
        }

        vector a(n, vector<int>(7));
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < 7; j++) {
                cin >> a[i][j];
            }
        }

        vector<int> b(2);
        cin >> b[0] >> b[1];

        TwoSat ts(N);

        auto index = [&](int contest, int day) {
            return id[day][abs(contest) - 1];
        };

        auto flag = [&](int contest) {
            return contest > 0;
        };

        for (int i = 0; i < n; i++) {
            for (int x = 0; x < 7; x++) {
                for (int y = x + 1; y < 7; y++) {
                    ts.add(index(a[i][x], x), !flag(a[i][x]), index(a[i][y], y), !flag(a[i][y]));
                }
            }
        }

        for (int i = 0; i < 2; i++) {
            ts.add(index(b[i], i + 5), flag(b[i]));
        }
        
        cout << (ts.satisfiable() ? "possible" : "impossible") << '\n';
    };
    
    solve();
    
    return 0;
}