#[allow(unused_imports)]
use std::cmp::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::iter::FromIterator;
#[allow(unused_imports)]
use std::io::stdin;
mod util {
    use std::io::stdin;
    use std::str::FromStr;
    use std::fmt::Debug;
    #[allow(dead_code)]
    pub fn line() -> String {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().to_string()
    }
    #[allow(dead_code)]
    pub fn gets<T: FromStr>() -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|t| t.parse().unwrap())
            .collect()
    }
}
#[allow(unused_macros)]
macro_rules ! get { ( $ t : ty ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . trim ( ) . parse ::<$ t > ( ) . unwrap ( ) } } ; ( $ ( $ t : ty ) ,* ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; let mut iter = line . split_whitespace ( ) ; ( $ ( iter . next ( ) . unwrap ( ) . parse ::<$ t > ( ) . unwrap ( ) , ) * ) } } ; ( $ t : ty ; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ ( $ t : ty ) ,*; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ ( $ t ) ,* ) ) . collect ::< Vec < _ >> ( ) } ; ( $ t : ty ;; ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . split_whitespace ( ) . map ( | t | t . parse ::<$ t > ( ) . unwrap ( ) ) . collect ::< Vec < _ >> ( ) } } ; }
#[allow(unused_macros)]
macro_rules ! debug { ( $ ( $ a : expr ) ,* ) => { println ! ( concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) ; } }

fn main() {
    let (n, m, k, s, t) = get!(usize, usize, i64, i64, i64);
    let abc = get!(usize, i64, i64; m);

    let mut edges = vec![Vec::new(); n - 1];
    for &(a, b, c) in &abc {
        edges[a - 1].push((b, c));
    }

    let mut dp = BTreeMap::new();
    dp.insert(s, 0);

    for es in edges.iter_mut() {
        if es.is_empty() {
            println!("-1");
            return;
        }

        es.sort();

        let v: Vec<(i64, i64)> = dp.into_iter().collect();
        dp = BTreeMap::new();

        let mut i = v.len();
        let mut cost = i64::max_value() / 4;

        for &(b, c) in es.iter().rev() {
            while i > 0 && v[i - 1].0 >= b {
                i -= 1;
                cost = min(cost, v[i].0 + v[i].1);
            }
            dp.insert(c, cost - b);
        }

        let mut i = 0;
        let mut cost = i64::max_value() / 4;

        for &(b, c) in es.iter().rev() {
            while i < v.len() && v[i].0 <= b {
                cost = min(cost, v[i].1 - v[i].0);
                i += 1;
            }
            let nc = cost + b;
            let v = dp.entry(c).or_insert(nc);
            *v = min(*v, nc);
        }
    }

    println!(
        "{}",
        dp.into_iter()
            .map(|(p, c)| c + (t - p).abs())
            .min()
            .unwrap()
    );
}