#include <iostream>
#include <cstdio>
#include <string>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <set>
#define Buff ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
using namespace std;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const int N = 5e4 + 5;
const ll mx = 1e9 + 3;

int n, m, s, t, cnt;
int head[N];
ll dist[N];

struct node
{
	int to, nexx;
	ll a, b, t;
}edge[N * 2];

void add(int u, int v, ll a, ll b, ll t)
{
	edge[cnt].to = v;
	edge[cnt].nexx = head[u];
	edge[cnt].a = a;
	edge[cnt].b = b;
	edge[cnt].t = t;
	head[u] = cnt++;
}

void solve()
{
	int TT = 1;
	while(cin >> n >> m >> s >> t)
	{
		memset(head, -1, sizeof(head));
		cnt = 0;
		vector<int> deg(n + 5, 0);
		for(int i = 1; i <= n; i++) dist[i] = 1e18;
		for(int i = 1; i <= m; i++)
		{
			int u, v;
			ll a, b, tt;
			cin >> u >> v >> a >> b >> tt;
			add(u, v, a, b, tt);
			add(v, u, a, b, tt);
			deg[u]++, deg[v]++;
		}

		queue < pair<int, ll >> q;
		q.push({s, 0});
		dist[s] = 0;
		while(q.size())
		{
			ll u = q.front().first, w = q.front().second;
			q.pop();

			for(int i = head[u]; i != -1; i = edge[i].nexx)
			{
				int to = edge[i].to;
				ll a = edge[i].a, b = edge[i].b, tt = edge[i].t;

				ll ww = w;
				int time = ww % (a + b);
				                                   
				if(time + tt <= a) ww = max(ww, w + tt);
				else ww = max(ww, w + (a + b - time) + tt);
				dist[to] = min(dist[to], max(dist[u], ww));
				deg[to]--;
				if(deg[to] == 1) q.push({to, ww});
			}
		}

		cout << "Case " << TT++ << ": ";
		cout << dist[t] << '\n';
	}
}

int main()
{
	Buff;
	int N = 1;
	//cin >> N;
	while(N--)
		solve();
	return 0;
}