package adv2017;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.InputMismatchException;

public class N614 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni(), m = ni(), K = ni(), s = ni(), t = ni();
		int[][] ws = new int[m][];
		for(int i = 0;i < m;i++){
			ws[i] = na(3);
		}
		Arrays.sort(ws, new Comparator<int[]>() {
			public int compare(int[] a, int[] b) {
				if(a[0] != b[0])return a[0] - b[0];
				return a[1] - b[1];
			}
		});
		long[][] xys = new long[][]{{s, -1, 0L}};
		int p = 0;
		long[][] nxs = new long[m+1][];
		for(int i = 1;i < n;i++){
			int q = 0;
			while(p < m && ws[p][0] == i){
				nxs[q++] = new long[]{ws[p][1], ws[p][2], Long.MAX_VALUE / 2};
				p++;
			}
			
			int r = 0;
			long min = Long.MAX_VALUE / 2;
			for(int j = 0;j < q;j++){
				while(r < xys.length && xys[r][0] <= nxs[j][1]){
					min = Math.min(min, xys[r][2] - xys[r][0]);
					r++;
				}
				nxs[j][2] = Math.min(nxs[j][2], min + nxs[j][0]);
			}
			
			r = xys.length-1;
			min = Long.MAX_VALUE / 2;
			for(int j = q-1;j >= 0;j--){
				while(r >= 0 && xys[r][0] >= nxs[j][1]){
					min = Math.min(min, xys[r][2] + xys[r][0]);
					r--;
				}
				nxs[j][2] = Math.min(nxs[j][2], min - nxs[j][0]);
			}
			xys = Arrays.copyOf(nxs, q);
			for(int j = 0;j < q;j++){
				xys[j][0] = xys[j][1];
				xys[j][1] = -1;
			}
			Arrays.sort(xys, new Comparator<long[]>() {
				public int compare(long[] a, long[] b) {
					return Long.compare(a[0], b[0]);
				}
			});
		}
		long ans = Long.MAX_VALUE / 2;
		for(long[] xy : xys){
			ans = Math.min(ans, xy[2] + Math.abs(xy[0] - t));
		}
		if(ans >= 1e18){
			out.println(-1);
		}else{
			out.println(ans);
		}
	}
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new N614().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}