#include<bits/stdc++.h>
using namespace std;
#define int long long
#define lowbit(x) x&-x
const int INF=0x3f3f3f3f3f3f3f3f;
const int N=1e5+10;
const int M=2e6+10;
struct node{
	int v,w,k;
};
vector<node>g[N];
int n,m,x,y;
struct cmp{
	bool operator()(pair<int,int>u,pair<int,int>v){
		return u.second>v.second;
	}
};
priority_queue<pair<int,int>,vector<pair<int,int>>,cmp>q;
int dis[N];
bool vis[N];
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
	cin>>n>>m>>x>>y;
	for(int i=1;i<=m;i++){
		int u,v,w,k;
		cin>>u>>v>>w>>k;
		g[u].push_back({v,w,k});
		g[v].push_back({u,w,k});
	}
	memset(dis,0x3f,sizeof(dis));
	q.push({x,0});
	dis[x]=0;
	while(!q.empty()){
		int u=q.top().first;
		q.pop();
		if(vis[u])	continue;
		vis[u]=1;
		for(auto p:g[u]){
			int v=p.v;
			int w=p.w;
			int k=p.k;
			int cnt=dis[u];
			if(cnt%k)	cnt=(dis[u]/k)*k+k;
			cnt+=w;
			if(dis[v]>cnt){
				dis[v]=cnt;
				q.push({v,cnt});
			}
		}
	}
	if(dis[y]==INF){
		cout<<-1;
		return 0;
	}
	cout<<dis[y];
    return 0;
}