import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int p = sc.nextInt() - 1;
		int q = sc.nextInt() - 1;
		long t = sc.nextInt();
		ArrayList<HashMap<Integer, Integer>> graph = new ArrayList<>();
		for (int i = 0; i < n; i++) {
		    graph.add(new HashMap<>());
		}
		for (int i = 0; i < m; i++) {
		    int a = sc.nextInt() - 1;
		    int b = sc.nextInt() - 1;
		    int c = sc.nextInt();
		    graph.get(a).put(b, c);
		    graph.get(b).put(a, c);
		}
		PriorityQueue<Path> queue = new PriorityQueue<>();
		long[] fromS = new long[n];
		queue.add(new Path(0, 0));
		search(queue, fromS, graph);
		long[] fromP = new long[n];
		queue.add(new Path(p, 0));
		search(queue, fromP, graph);
		long[] fromQ = new long[n];
		queue.add(new Path(q, 0));
		search(queue, fromQ, graph);
		if (fromS[p] + fromS[q] + fromP[q] <= t) {
		    System.out.println(t);
		    return;
		}
		long max = -1;
		for (int i = 0; i < n; i++) {
		    if ((fromS[i] + Math.max(fromP[i], fromQ[i])) * 2 <= t) {
		        max = Math.max(max, t - Math.max(fromP[i], fromQ[i]) * 2);
		    }
		}
		System.out.println(max);
	}
	
	static class Path implements Comparable<Path> {
	    int idx;
	    long value;
	    
	    public Path(int idx, long value) {
	        this.idx = idx;
	        this.value = value;
	    }
	    
	    public int compareTo(Path another) {
	        if (value == another.value) {
	            return 0;
	        } else if (value < another.value) {
	            return -1;
	        } else {
	            return 1;
	        }
	    }
	}
	
	static void search(PriorityQueue<Path> queue, long[] costs, ArrayList<HashMap<Integer, Integer>> graph) {
		Arrays.fill(costs, Long.MAX_VALUE / 10);
		while (queue.size() > 0) {
		    Path p = queue.poll();
		    if (costs[p.idx] <= p.value) {
		        continue;
		    }
		    costs[p.idx] = p.value;
		    for (Map.Entry<Integer, Integer> entry : graph.get(p.idx).entrySet()) {
		        if (costs[entry.getKey()] == Long.MAX_VALUE / 10) {
		            queue.add(new Path(entry.getKey(), p.value + entry.getValue()));
		        }
		    }
		}
	}
}