import java.io.*;
import java.lang.reflect.Array;
import java.util.*;
import java.util.Map.Entry;
import java.util.function.Function;
import java.util.stream.Collectors;

@SuppressWarnings("unused")
public class Main {
	FastScanner in = new FastScanner(System.in);
	PrintWriter out = new PrintWriter(System.out);
	final int MOD = (int)1e9+7;
	
	//System.out.println();はつかわない！！
	void solve() throws Exception{
		int N = in.nextInt(), M = in.nextInt();
		int P = in.nextInt()-1, Q = in.nextInt()-1;
		int T = in.nextInt();
		long INF = Long.MAX_VALUE / 2;
		
		ArrayList<ArrayList<Edge>> G = new ArrayList<>();
		for(int i = 0; i < N; i++) G.add(new ArrayList<>());
		for(int i = 0; i < M; i++){
			int a = in.nextInt()-1, b = in.nextInt()-1;
			int c = in.nextInt();
			G.get(a).add(new Edge(a, b, c));
			G.get(b).add(new Edge(b, a, c));
		}
		
		long[] dist1 = dijkstra(G, 0), distP = dijkstra(G, P), distQ = dijkstra(G, Q);
		long ans = -1;
		for(int u = 0; u < N; u++){
			if(dist1[u] == INF || distP[u] == INF || distQ[u] == INF) continue;
			for(int v = 0; v < N; v++){
				if(dist1[v] == INF || distP[v] == INF || distQ[v] == INF) continue;
				long distA = dist1[u] + distP[u] + distP[v] + dist1[v];
				long distB = dist1[u] + distQ[u] + distQ[v] + dist1[v];
				if(!(distA <= T && distB <= T)) continue;
				
				long dist = dist1[u] + Math.min(T - (dist1[u] + distP[u] + distP[v]), T - (dist1[u] + distQ[u] + distQ[v]));
				if(u == P && v == Q) dist += distP[u] + distP[v];
				ans = Math.max(ans, dist);
			}
		}
		out.println(ans);
	}
	
	long[] dijkstra(ArrayList<ArrayList<Edge>> G, int start){
		long INF = Long.MAX_VALUE / 2;
		long[] dist = new long[G.size()];
		Arrays.fill(dist, INF);
		dist[start] = 0;
		PriorityQueue<Node> priorityQueue = new PriorityQueue<Node>();
		priorityQueue.add(new Node(start, 0));
		
		while(!priorityQueue.isEmpty()){
			Node node = priorityQueue.poll();
			if(dist[node.index] < node.cost) continue;
			for(Edge e : G.get(node.index)){
				if(dist[e.to] > dist[node.index] + e.cost){
					dist[e.to] = dist[node.index] + e.cost;
					priorityQueue.add(new Node(e.to, dist[e.to]));
				}
			}
		}
		
		return dist;
	}
	
	class Node implements Comparable<Node>{
		int index;
		long cost;
		public Node(int i, long c){
			index = i; cost = c;
		}
		@Override
		public int compareTo(Node o) {
			return Long.compare(this.cost, o.cost);
		}
	}

	class Edge implements Comparable<Edge>{
		int from;
		int to;
		long cost;
		public Edge(int f, int t, long c){
			from = f;to = t;cost = c;
		}
		@Override
		public int compareTo(Edge o) {
			return Long.compare(this.cost, o.cost);
		}
	}
	
	public static void main(String[] args) throws Exception {
		new Main().m();
	}
	
	void m() throws Exception {
		solve();
		out.flush();
	}
	
	class FastScanner {
		Reader input;

		FastScanner() {this(System.in);}
		FastScanner(InputStream stream) {this.input = new BufferedReader(new InputStreamReader(stream));}
		
		int nextInt() {return (int) nextLong();}

		long nextLong() {
			try {
				int sign = 1;
				int b = input.read();
				while ((b < '0' || '9' < b) && b != '-' && b != '+') {
					b = input.read();
				}
				if (b == '-') {
					sign = -1;
					b = input.read();
				} else if (b == '+') {
					b = input.read();
				}
				long ret = b - '0';
				while (true) {
					b = input.read();
					if (b < '0' || '9' < b) return ret * sign;
					ret *= 10;
					ret += b - '0';
				}
			} catch (IOException e) {
				e.printStackTrace();
				return -1;
			}
		}

		double nextDouble() {
			try {
				double sign = 1;
				int b = input.read();
				while ((b < '0' || '9' < b) && b != '-' && b != '+') {
					b = input.read();
				}
				if (b == '-') {
					sign = -1;
					b = input.read();
				} else if (b == '+') {
					b = input.read();
				}
				double ret = b - '0';
				while (true) {
					b = input.read();
					if (b < '0' || '9' < b) break;
					ret *= 10;
					ret += b - '0';
				}
				if (b != '.') return sign * ret;
				double div = 1;
				b = input.read();
				while ('0' <= b && b <= '9') {
					ret *= 10;
					ret += b - '0';
					div *= 10;
					b = input.read();
				}
				return sign * ret / div;
			} catch (IOException e) {
				e.printStackTrace();
				return Double.NaN;
			}
		}

		char nextChar() {
			try {
				int b = input.read();
				while (Character.isWhitespace(b)) {
					b = input.read();
				}
				return (char) b;
			} catch (IOException e) {
				e.printStackTrace();
				return 0;
			}
		}

		String nextStr() {
			try {
				StringBuilder sb = new StringBuilder();
				int b = input.read();
				while (Character.isWhitespace(b)) {
					b = input.read();
				}
				while (b != -1 && !Character.isWhitespace(b)) {
					sb.append((char) b);
					b = input.read();
				}
				return sb.toString();
			} catch (IOException e) {
				e.printStackTrace();
				return "";
			}
		}
		
		public int[] nextIntArray(int n) {
			int[] res = new int[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextInt();
			}
			return res;
		}
 
		public int[] nextIntArrayDec(int n) {
			int[] res = new int[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextInt() - 1;
			}
			return res;
		}
 
		public int[] nextIntArray1Index(int n) {
			int[] res = new int[n + 1];
			for (int i = 0; i < n; i++) {
				res[i + 1] = nextInt();
			}
			return res;
		}
 
		public long[] nextLongArray(int n) {
			long[] res = new long[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextLong();
			}
			return res;
		}
 
		public long[] nextLongArrayDec(int n) {
			long[] res = new long[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextLong() - 1;
			}
			return res;
		}
 
		public long[] nextLongArray1Index(int n) {
			long[] res = new long[n + 1];
			for (int i = 0; i < n; i++) {
				res[i + 1] = nextLong();
			}
			return res;
		}
 
		public double[] nextDoubleArray(int n) {
			double[] res = new double[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextDouble();
			}
			return res;
		}
	}
}
/* end Main */