import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] first = br.readLine().split(" ", 5);
        int n = Integer.parseInt(first[0]);
        int m = Integer.parseInt(first[1]);
        int k = Integer.parseInt(first[2]);
        int s = Integer.parseInt(first[3]);
        int t = Integer.parseInt(first[4]);
        ArrayList<ArrayList<Route>> graph = new ArrayList<>();
        for (int i = 0; i < n - 1; i++) {
            graph.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            String[] line = br.readLine().split(" ", 3);
            int a = Integer.parseInt(line[0]) - 1;
            int b = Integer.parseInt(line[1]);
            int c = Integer.parseInt(line[2]);
            graph.get(a).add(new Route(b, c));
        }
        ArrayList<HashMap<Integer, Long>> costs = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            costs.add(new HashMap<>());
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        queue.add(new Path(0, s, 0));
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (costs.get(p.idx).containsKey(p.floor)) {
                continue;
            }
            costs.get(p.idx).put(p.floor, p.value);
            if (p.idx == n - 1) {
                continue;
            }
            for (Route x : graph.get(p.idx)) {
                if (!costs.get(p.idx + 1).containsKey(x.end)) {
                    queue.add(new Path(p.idx + 1, x.end, p.value + Math.abs(p.floor - x.start)));
                }
            }
        }
        long min = Long.MAX_VALUE;
        for (Map.Entry<Integer, Long> entry : costs.get(n - 1).entrySet()) {
            int key = entry.getKey();
            long value = entry.getValue();
            min = Math.min(min, Math.abs(key - t) + value);
        }
        if (min == Long.MAX_VALUE) {
            System.out.println(-1);
        } else {
            System.out.println(min);
        }
    }
    
    static class Path implements Comparable<Path> {
        int idx;
        int floor;
        long value;
        
        public Path(int idx, int floor, long value) {
            this.idx = idx;
            this.floor = floor;
            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 class Route {
        int start;
        int end;
        
        public Route(int start, int end) {
            this.start = start;
            this.end = end;
        }
    }
}