#include <iostream>
#include <vector>
#include <queue>

using namespace std;
using ll = long long;
const ll INF = 1ll<<60;

struct Edge{
    int to;
    int weight;
    int k;
    Edge(int t, int w, int k): to(t), weight(w), k(k) {}
};

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

    int n, m, x, y;
    cin >> n >> m >> x >> y;
    --x;
    --y;
    
    vector<vector<Edge>> g(n);

    for(int i = 0; i < m; ++i){
        int a, b, t, k;
        cin >> a >> b >> t >> k;
        --a;
        --b;
        g[a].push_back(Edge(b, t, k));
        g[b].push_back(Edge(a, t, k));
    }

    vector<ll> dist(n, INF);
    dist[x] = 0;
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
    pq.push({0, x});

    while(!pq.empty()){
        pair<ll, int> p = pq.top();
        pq.pop();
        int v = p.second;

        if(dist[v] != p.first) continue;

        for(auto ne: g[v]){
            ll ndist = ((dist[v] + ne.k - 1) / ne.k) * ne.k;
            // if(ndist % ne.k != 0) ndist += ne.k - ndist%ne.k;
            ndist += ne.weight;

            if(ndist < dist[ne.to]){
                dist[ne.to] = ndist;
                pq.push({dist[ne.to], ne.to});
            }
        }
    }

    if(dist[y] == INF) cout << -1 << endl;
    else cout << dist[y] << endl;

//    cout << endl;

//    for(auto e: dist) cout << e << " ";
//    cout << endl;

    return 0;
}

//*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//*/
 
#include <bits/stdc++.h>
 
// #include <atcoder/all>
 
using namespace std;
// using namespace atcoder;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
// #define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
void YES(bool t=true) {cout<<(t?"YES":"NO")<<endl;}
void Yes(bool t=true) {cout<<(t?"Yes":"No")<<endl;}
void yes(bool t=true) {cout<<(t?"yes":"no")<<endl;}
void NO(bool t=true) {cout<<(t?"NO":"YES")<<endl;}
void No(bool t=true) {cout<<(t?"No":"Yes")<<endl;}
void no(bool t=true) {cout<<(t?"no":"yes")<<endl;}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
int popcount(ll t) { return __builtin_popcountll(t); }
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {0, 1, 0, -1}, dy = {-1, 0, 1, 0};
// vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
struct Setup_io {
    Setup_io() {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        cout << fixed << setprecision(25);
    }
} setup_io;
const ll MOD = 1000000007;
// const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

const int N = 100123;
using P = pair<int, pll>;
vector<vector<P>> G(N);

vl dijkstra(int s, int n){
	priority_queue<pll, vector<pll>, greater<pll> > pq;
	int i;
	vl d(n, INF);
	d[s]=0;
	pq.push(make_pair(0,s));
	
	while(!pq.empty()){
		pll f=pq.top();
		pq.pop();
		int u=f.second;
		if(d[u]<f.first){
			continue;
		}
        ll cost = f.first;
		for (i = 0; i < G[u].size(); i++) {
			int v=G[u][i].first;
            ll ncost;
            ll k = G[u][i].second.second;
            if (cost % k == 0) {
                ncost = cost;
            }
            else {
                ncost = cost / k * k + k;
            }
            ncost += G[u][i].second.first;
			if (d[v] > ncost) {
				d[v] = ncost;
				pq.push(make_pair(d[v], v));
			}
		}
	}
	return d;
}


signed main() {
    int n, m, x, y;
    cin >> n >> m >> x >> y;
    x--; y--;
    rep (i, m) {
        int u, v, t, k;
        cin >> u >> v >> t >> k;
        u--; v--;
        G[u].push_back(P(v, pll(t, k)));
        G[v].push_back(P(u, pll(t, k)));
    }

    vl d = dijkstra(x, n);
    if (d[y] == INF) {
        cout << -1 << endl;
    }
    else {
        cout << d[y] << endl;
    }
}