// 各辺にコスト1を割り当て，x->y, x->z に流量 2 の最小費用流を流し，x->y のパスを固定して
// 残りの頂点と辺で z->x, z->y に流量 2 の最小費用流を流す
#include <algorithm>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;

#include <cassert>
#include <tuple>

namespace INPUT {
using namespace std;

tuple<int, int, int, int, vector<vector<int>>> read() {
    int N, M, X, Y, Z;
    cin >> N >> M >> X >> Y >> Z;
    --X, --Y, --Z;
    vector mat(N, vector<int>(N));
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < N; ++j) { mat[i][j] = (i != j); }
    }
    while (M--) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        mat[a][b] = mat[b][a] = 0;
    }
    vector<vector<int>> to(N);
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < N; ++j) {
            if (mat[i][j]) to[i].push_back(j);
        }
    }
    return {N, X, Y, Z, to};
}
}; // namespace INPUT
#line 3 "twopaths.hpp"
#include <atcoder/mincostflow>
#line 8 "twopaths.hpp"

// 各辺にコスト1を割り当て，x->y, x->z に流量 2 の最小費用流を流し，x->y のパスを固定して
// 残りの頂点と辺で z->x, z->y に流量 2 の最小費用流を流す

namespace TWOPATHS {
using namespace std;

// used_vs に含まれる頂点は使わずに，from -> to1 と from->to2 の点素なパスを構成する．
// 両方のパスが構築できなければ empty vector の組を返す．
pair<vector<int>, vector<int>> twopaths(const vector<vector<int>> &to, const vector<int> &used_vs, int from, int to1, int to2) {
    const int N = to.size();
    const int gt = N * 2;
    atcoder::mcf_graph<int, int> graph(gt + 1);

    vector<int> valid_v(N, 1);
    for (auto i : used_vs) valid_v[i] = 0;

    valid_v[to1] = valid_v[to2] = 0;

    for (int i = 0; i < N; ++i) { graph.add_edge(i, i + N, valid_v[i], 0); }
    graph.add_edge(to1, to1 + N, 1, 0);
    graph.add_edge(to2, to2 + N, 1, 0);

    for (int i = 0; i < N; ++i) {
        for (auto j : to[i]) {
            int cost = 1;
            graph.add_edge(i + N, j, 1, cost);
        }
    }
    graph.add_edge(to1 + N, gt, 1, 0);
    graph.add_edge(to2 + N, gt, 1, 0);
    auto f = graph.flow(from + N, gt, 2);
    if (f.first < 2) return {{}, {}};

    vector<vector<int>> conn(N);
    for (auto e : graph.edges()) {
        if (e.flow) {
            if (e.to == gt) continue;
            int s = e.from % N, t = e.to % N;
            if (s != t) conn[s].push_back(t);
        }
    }

    vector<vector<int>> ret;
    while (conn[from].size()) {
        int now = from;
        vector<int> vec{now};
        while (conn[now].size()) {
            int nxt = conn[now].back();
            conn[now].pop_back();
            now = nxt;
            vec.push_back(now);
        }
        ret.push_back(vec);
    }
    assert(ret.size() == 2);
    if (ret[0].back() != to1) swap(ret[0], ret[1]);
    if (ret[1].back() != to2) swap(ret[0], ret[1]);
    return {ret.at(0), ret.at(1)};
}

constexpr int inf = 1 << 20;

int solve_fake_flow_sub(const vector<vector<int>> &to, const vector<int> &banxy, int z, int x, int y) {
    auto [p1, p2] = twopaths(to, banxy, z, x, y);
    if (p1.empty()) return inf;
    return p1.size() + p2.size() + banxy.size() - 1;
}

int solve_by_flow_twice(const vector<vector<int>> &to, int x, int y, int z) {

    int N = to.size();
    vector<int> vs{x, y, z};
    sort(vs.begin(), vs.end());
    int ret = inf;

    do {
        auto [p01, p02] = twopaths(to, {}, vs[0], vs[1], vs[2]);
        if (p01.empty() or p02.empty()) continue;
        auto ban01 = p01, ban02 = p02;
        for (int t = 0; t < 2; ++t) {
            ban01.pop_back(), ban02.pop_back();
            reverse(ban01.begin(), ban01.end()), reverse(ban02.begin(), ban02.end());
        }
        ret = min(ret, solve_fake_flow_sub(to, ban01, vs[2], vs[0], vs[1]));
        ret = min(ret, solve_fake_flow_sub(to, ban02, vs[1], vs[0], vs[2]));
    } while (next_permutation(vs.begin(), vs.end()));

    for (int u = 0; u < 3; ++u) {
        auto [p01a, p01b] = twopaths(to, {}, vs[0], vs[1], vs[1]);
        if (p01a.empty()) continue;
        if (count(p01a.begin(), p01a.end(), vs[2]) or count(p01b.begin(), p01b.end(), vs[2])) {
            ret = min<int>(ret, p01a.size() + p01b.size() - 2);
        } else {
            auto ban01a = p01a, ban01b = p01b;
            for (int t = 0; t < 2; ++t) {
                ban01a.pop_back(), ban01b.pop_back();
                reverse(ban01a.begin(), ban01a.end()), reverse(ban01b.begin(), ban01b.end());
            }
            ret = min(ret, solve_fake_flow_sub(to, ban01a, vs[2], vs[0], vs[1]));
            ret = min(ret, solve_fake_flow_sub(to, ban01b, vs[2], vs[0], vs[1]));
        }
        rotate(vs.begin(), vs.begin() + 1, vs.end());
    }

    return ret <= N ? ret : -1;
}
}
#line 11 "uso_determin.cpp"

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

    auto [N, X, Y, Z, to] = INPUT::read();

    int ret = TWOPATHS::solve_by_flow_twice(to, X, Y, Z);
    cout << ret << '\n';
}