import java.util.*;

public class Main {
    static final long MAX = Long.MAX_VALUE / 10;
	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;
    	int 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<>();
    	queue.add(new Path(p, 0));
    	long[] pCosts = getCost(n, queue, graph);
    	queue.add(new Path(q, 0));
    	long[] qCosts = getCost(n, queue, graph);
    	queue.add(new Path(0, 0));
    	long[] zCosts = getCost(n, queue, graph);
    	if (Math.max(pCosts[0], qCosts[0]) * 2 > t) {
    	    System.out.println(-1);
    	    return;
    	}
    	if (pCosts[0] + pCosts[q] + qCosts[0] <= t) {
    	    System.out.println(t);
    	    return;
    	}
    	long max = 0;
    	for (int i = 0; i < n; i++) {
    	    for (int j = 0; j < n; j++) {
    	        if (Math.max(pCosts[i] + pCosts[j], qCosts[i] + qCosts[j]) + zCosts[i] + zCosts[j] <= t) {
    	            max = Math.max(max, t - Math.max(pCosts[i] + pCosts[j], qCosts[i] + qCosts[j]));
    	        }
    	    }
    	}
    	System.out.println(max);
    }
    
    static long[] getCost(int size, PriorityQueue<Path> queue, ArrayList<HashMap<Integer, Integer>> graph) {
        long[] costs = new long[size];
        Arrays.fill(costs, MAX);
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (costs[p.idx] <= p.value) {
                continue;
            }
            costs[p.idx] = p.value;
            for (int x : graph.get(p.idx).keySet()) {
                queue.add(new Path(x, p.value + graph.get(p.idx).get(x)));
            }
        }
        return costs;
    }
    
    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;
            }
        }
    }
}