#include <string>
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;
typedef long long int ll;

#define x first
#define y second

#define NONE 1234567890

struct Vertex {
    vector<int> next;
    vector<ll> firstEnemy;
    ll distance = NONE;
    Vertex() : firstEnemy(2, NONE) {};
};

int main(){
    ll n, m, finish, enemyStart, start, a, b;
    cin >> n >> m >> finish >> enemyStart >> start;
    vector<Vertex> graph(n);
    vector<pair<int, int>> edges(m);
    if (start == enemyStart) {
        cout << "death\n";
        return 0;
    }
    for (int i=0; i<m; i++) {
        cin >> a >> b;
        graph[a].next.push_back(b);
        graph[b].next.push_back(a);
        edges[i] = {a, b};
    }
    queue<pair<ll, ll>> q;
    graph[enemyStart].firstEnemy[0] = 0;
    q.push({0, enemyStart});
    while (!q.empty()){
        ll d = q.front().first;
        ll v = q.front().second;
        q.pop();
        for (int s: graph[v].next) {
            if (graph[s].firstEnemy[(d+1) % 2] == NONE) {
                graph[s].firstEnemy[(d+1) % 2] = d + 1;
                q.push({d+1, s});
            }
        }
    }
    //vstupne su < n, vystupne su n az 2*n-1
    vector<Vertex> ourGraph(2*n);
    for (int i=0; i<n; i++){
        ourGraph[i].next.push_back(i+n);
        ourGraph[i].firstEnemy = graph[i].firstEnemy;
        ourGraph[i+n].firstEnemy = graph[i].firstEnemy;
    }
    for (auto &p: edges) {
        ourGraph[p.first + n].next.push_back(p.second);
        ourGraph[p.second + n].next.push_back(p.first);
        ourGraph[p.first].next.push_back(p.second);
        ourGraph[p.second].next.push_back(p.first);
    }

    q = queue<pair<ll, ll>>();
    q.push({0, start});
    ourGraph[start].distance = 0;
    while (!q.empty()) {
        ll d = q.front().first;
        ll v = q.front().second;
        q.pop();
        for (int s: ourGraph[v].next) {
            if (ourGraph[s].distance == NONE && ourGraph[s].firstEnemy[(d+1)%2] > d+1) {
                ourGraph[s].distance = d + 1;
                q.push({d+1, s});
            }
        }
    }
    if (ourGraph[finish].distance == NONE) {
        cout << "death\n";
    }
    else {
        cout << ourGraph[finish].distance << '\n';
    }
    return 0;
}