//  ____            _                  _                       _       _
// |  _ \ _   _ ___| |_    ___ _ __   | |_ ___ _ __ ___  _ __ | | __ _| |_ ___
// | |_) | | | / __| __|  / __| '_ \  | __/ _ \ '_ ` _ \| '_ \| |/ _` | __/ _ \
// |  _ <| |_| \__ \ |_  | (__| |_) | | ||  __/ | | | | | |_) | | (_| | ||  __/
// |_| \_\\__,_|___/\__|  \___| .__/___\__\___|_| |_| |_| .__/|_|\__,_|\__\___|
//                            |_| |_____|               |_|

//                                                     _        _ _ _____  ___
//                               _ __ ___   __ _ _ __ | |_ __ _/ / |___ / / _ \
//                              | '_ ` _ \ / _` | '_ \| __/ _` | | | |_ \| | | |
//                              | | | | | | (_| | | | | || (_| | | |___) | |_| |
//                              |_| |_| |_|\__,_|_| |_|\__\__,_|_|_|____/ \___/

//https://github.com/manta1130/Competitive_Programming_Template_Rust

#[macro_use]
mod input {

    use std;
    use std::io;

    const SPLIT_DELIMITER: char = ' ';

    /// 空白で区切られた複数の値の読み込む。
    /// # Example
    /// ```ignore
    /// use cp_template::*;
    ///
    /// let (a,b):(usize,usize);
    /// input!(a,b);
    /// ```
    #[macro_export]
    #[allow(unused_macros)]
    macro_rules! input {
    ( $($x:expr ),*) => {
        {
            let temp_str = input_line_str();
            let mut split_result_iter = temp_str.split_whitespace();
                $(
                let buf_split_result = split_result_iter.next();
                let buf_split_result = buf_split_result.unwrap();
                    ($x) = buf_split_result.parse().unwrap();
                )*
        }
    };
}

    /// 文字列を一行読み込む
    /// # Example
    /// ```ignore
    /// use cp_template::*;
    ///
    /// let s = input_line_str();
    /// ```
    #[allow(dead_code)]
    pub fn input_line_str() -> String {
        let mut s = String::new();
        io::stdin().read_line(&mut s).unwrap();
        s.trim().to_string()
    }

    /// 一つの変数を出力する。
    /// ```
    /// use cp_template::*;
    ///
    /// let a=100;
    /// p(a);
    /// //上と下は等価です。
    /// println!("{}",a);
    /// ```
    #[allow(dead_code)]
    pub fn p<T>(t: T)
    where
        T: std::fmt::Display,
    {
        println!("{}", t);
    }

    /// 指定した行数を読み込み、二次元配列に変換する。
    /// # Examples
    /// ```ignore
    /// use cp_template::*;
    ///
    /// //10行読み込む。
    /// let v = input_vector2d::<usize>(10);
    /// ```
    #[allow(dead_code)]
    pub fn input_vector2d<T>(line: usize) -> Vec<Vec<T>>
    where
        T: std::str::FromStr,
    {
        let mut v: Vec<Vec<T>> = Vec::new();

        for _ in 0..line {
            let vec_line = input_vector();
            v.push(vec_line);
        }
        v
    }

    /// 一行読み込み、配列(Vec)に変換する。
    /// # Examples
    /// ```ignore
    /// use cp_template::*;
    ///
    /// let v=input_vector::<usize>();
    /// ```
    #[allow(dead_code)]
    pub fn input_vector<T>() -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v: Vec<T> = Vec::new();

        let s = input_line_str();
        let split_result = s.split(SPLIT_DELIMITER);
        for z in split_result {
            let buf = match z.parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error"),
            };
            v.push(buf);
        }
        v
    }

    ///　指定された行数を読み込む
    #[allow(dead_code)]
    pub fn input_vector_row<T>(n: usize) -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::with_capacity(n);
        for _ in 0..n {
            let buf = match input_line_str().parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error"),
            };
            v.push(buf);
        }
        v
    }

    /// StringをVec<char>に変換するトレイト
    pub trait ToCharVec {
        fn to_charvec(&self) -> Vec<char>;
    }

    impl ToCharVec for String {
        fn to_charvec(&self) -> Vec<char> {
            self.to_string().chars().collect::<Vec<_>>()
        }
    }
}

//提出時は下と一番下のコメントアウトを外す。
mod graph {

use std;
use std::cmp;
use std::collections::BinaryHeap;

///最短経路計算(ベルマンフォード法)
///
///戻り値がtrueなら負の閉路がある。
///
///graph:グラフ情報(隣接リスト)
///
///dist:最短経路を格納する配列
///
///事前に始点には0を入れ、その他はNoneで初期化する必要がある。
pub fn bellman_ford(graph: &Vec<Vec<(usize, isize)>>, dist: &mut Vec<Option<isize>>) -> Vec<bool> {
    //負の閉路検出用
    let mut neg_flag = vec![false; dist.len()];

    for _ in 0..graph.len() {
        for (from, v) in graph.iter().enumerate() {
            for e in v {
                let cost = e.1;
                let to = e.0;
                if let Some(x) = dist[from] {
                    if let None = dist[to] {
                        dist[to] = Some(x + cost);
                    } else if let Some(y) = dist[to] {
                        if y > x + cost {
                            dist[to] = Some(x + cost);
                        }
                    }
                }
            }
        }
    }

    for _ in 0..graph.len() {
        for (from, v) in graph.iter().enumerate() {
            for e in v {
                let cost = e.1;
                let to = e.0;
                if let Some(x) = dist[from] {
                    if let None = dist[to] {
                        dist[to] = Some(x + cost);
                        neg_flag[to] = true;
                    } else if let Some(y) = dist[to] {
                        if y > x + cost {
                            dist[to] = Some(x + cost);
                            neg_flag[to] = true;
                        }
                    }
                }
                if neg_flag[from] {
                    neg_flag[to] = true;
                }
            }
        }
    }
    neg_flag
}

///最短経路計算(ダイクストラ法)
///
///最短経路が格納された配列を返す。
///
///graph:グラフ情報(隣接リスト)
///
///start:始点
pub fn dijkstra(graph: &Vec<Vec<(usize, isize)>>, start: usize) -> Vec<Option<isize>> {
    let mut heap = BinaryHeap::new();
    let mut dist = vec![None; graph.len()];
    dist[start] = Some(0);
    for e in &graph[start] {
        heap.push((dist[start].unwrap() - 1 * e.1, e.0));
    }

    while !heap.is_empty() {
        let e = heap.pop().unwrap();
        if let Some(x) = dist[e.1] {
            if x < -1 * e.0 {
                continue;
            }
        }
        dist[e.1] = Some(-1 * e.0);
        for next_e in &graph[e.1] {
            if dist[next_e.0] == None {
                heap.push(((-1 * (dist[e.1].unwrap() + next_e.1)), next_e.0));
            }
        }
    }
    dist
}

///最短経路計算(ワーシャルフロイド法)
pub fn warshall_floyd(graph: &mut Vec<Vec<isize>>) {
    for k in 0..graph.len() {
        for i in 0..graph.len() {
            for j in 0..graph.len() {
                graph[i][j] = cmp::min(graph[i][j], graph[i][k] + graph[k][j]);
            }
        }
    }
}

}


use graph::*;
use input::*;

fn main() {
    let (n, m, p): (usize, usize, isize);
    input!(n, m, p);
    let mut v = vec![vec![]; n];
    for _ in 0..m {
        let (a, b, c): (usize, usize, isize);
        input!(a, b, c);
        v[a - 1].push((b - 1, -1 * c + p));
    }

    let mut dist = vec![None; n];
    dist[0] = Some(0);

    let neg = bellman_ford(&v, &mut dist);
    if neg[n - 1] {
        println!("-1");
    } else {
        if dist[n - 1].unwrap() > 0 {
            println!("0");
        } else {
            println!("{}", -1 * dist[n - 1].unwrap());
        }
    }
}




Measured memory_bytes: 4352