#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<(n); ++i)
#define rep2(i, s, n) for(int i=s; i<(n); ++i)
#define ALL(v) (v).begin(), (v).end()

using namespace std;

typedef long long ll;

template<typename T>
using priority_queue_rev = priority_queue<T, vector<T>, greater<T> >;

static const int INTINF = (2147483647 >> 1); // 10^9 + 5000
static const ll LLINF = (9223372036854775807 >> 1);
static const int MAX = 1e5+1;
static const ll MOD = 1e9+7;

namespace Kunitaka{
    template<
        typename TYPE,
        std::size_t SIZE
    >
    std::size_t array_length(const TYPE (&array)[SIZE])
    {
        return SIZE;
    }

    template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
    template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
}
using namespace Kunitaka;
namespace Printer{
    void br(){
        cout << endl;
    }

    void loop_cnt(int i){
        cout << "i = " << i << endl;
    }

    void loop_cnt(int i, int j){
        cout << "i = " << i << ", " << "j = " << j << endl;
    }

    template<class T>
    void print(T x){
        cout << x << endl;
    }

    template<class T, class S>
    void print(T x, S y){
        cout << x << "," << y << endl;
    }

    template<class T, class S, class U>
    void print(T x, S y, U z){
        cout << x << "," << y << "," << z << endl;
    }

    template<class T, class S>
    void print(pair<T, S> p){
        cout << p.first << ", " << p.second << endl;
    }

    template<
        typename TYPE,
        std::size_t SIZE
    >
    void print(const TYPE (&array)[SIZE]){
        int lim = array_length(array);
        for(int i=0; i<lim; i++){
            if(i) cout << " ";
            cout << array[i];
        }
        cout << endl;
    }

    template<class S>
    void print(vector<S> v){
        for(int i=0; i<v.size(); i++){
            if(i) cout << " ";
            cout<< v[i];
        }
        cout << endl;
    }

    template<class S>
    void print(vector<vector<S> > vv){
        for(int i=0; i<vv.size(); i++){
            for(int j=0; j<vv[i].size(); j++){
                if(j) cout << " ";
                cout << vv[i][j];
            }
            cout << endl;
        }
    }

    void yesno(bool x){
        if(x) cout << "Yes" << endl;
        else cout << "No" << endl;
    }
};
using namespace Printer;

const int MAX_E = 5010;
const int MAX_V = 3010;

struct edge {int from, to, cost;};
edge es[MAX_E]; // 辺
bool canRea[MAX_V];
vector<vector<int> > g;

int d[MAX_V]; // 最短距離
int V, E; // Vは頂点数, Eは辺数

// s番目の頂点から各頂点への最短距離を求める
bool shortest_path(int s){
    for(int i=0; i<V; i++) d[i] = INTINF;
    d[s] = 0;
    int cnt = 0;
    bool hasHeiroMinus = false;
    while(true){
        bool update = false;
        for(int i=0; i<E; i++){
            edge e = es[i];
            int tmp = d[e.from] + e.cost;
            if(!canRea[e.to]) continue;
            if(d[e.from] != INTINF && d[e.to] > tmp){
                d[e.to] = d[e.from] + e.cost;
                update = true;
            }
        }
        if(!update) break;
        cnt++;
        if(cnt >= V+1){
            hasHeiroMinus = true;
            break;
        }
        // print(cnt);
    }

    return hasHeiroMinus;
}

vector<bool> used(MAX_V);
void calc(int v){
    for(int u : g[v]){
        if(used[u]) continue;
        canRea[u] = true;
        used[u] = true;
        calc(u);
    }
}





int main(int argc, const char * argv[]) {
    //提出時、消す----//
    //--------------//


    // input
    cout << fixed << setprecision(10);
    int N, M, P; cin >> N >> M >> P;
    g.resize(N);
    memset(canRea, 0, sizeof(canRea));
    canRea[N-1] = true;
    rep(i, M){
        int a, b, c; cin >> a >> b >> c;
        a--; b--;
        c -= P;
        es[i] = {a, b, -c};
        g[b].push_back(a);
    }
    V = N; E = M;

    calc(N-1);

    if(shortest_path(0)){
        cout << -1 << endl;
        return 0;
    }


    // rep(i, N){
    //     cout << canRea[i] << " ";
    // }
    // cout << endl;

    // rep(i, N){
    //     cout << d[i] << " ";
    // }
    // cout << endl;

    if(-d[N-1] < 0){
        cout << 0 << endl;
    }
    else{
        print(-d[N-1]);
    }
    
    
    return 0;
}


Measured memory_bytes: 512