#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> // Common file
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define eb emplace_back
#define emp emplace
#define ins insert
#define mp make_pair
#define mt make_tuple
#define sz(s) (int)s.size()
#define forp(i,a,b) for( int i=a;i<=b;i++)
#define rep(i,n)    for( int i=0;i<n;i++)
#define ren(i,n)    for( int i=n-1;i>=0;i--)
#define forn(i,a,b) for( int i=a;i>=b;i--)
#define w(t) while(t)
#define sc(a) scanf("%d", &a);
#define on cout<<"\n"
#define os cout <<" "
#define o2(a,b) cout<<a<<" "<<b
#define o(a) cout << a
#define ppr(a) cout << a.first << " " << a.second
#define bitcount __builtin_popcount
#define gcd __gcd
#define all(v) v.begin(),v.end()
#define mem(n,m) memset(n,m,sizeof(n))
#define pii pair<int,int>
#define tiii tuple<int, int, int>
#define pll pair<long long,long long>
#define sii set<int>
#define sll set<long long>
#define vii vector<int>
#define vll vector<long long>
#define mii map<int,int>
#define mll map<long long, long long>
#define lob lower_bound
#define upb upper_bound
#define ret return
#define present(s,x) (s.find(x) != s.end())
#define cpresent(s,x) (find(all(s),x) != s.end())
#define ford(container, it) for(auto it = container.begin(); it != container.end(); it++)
#define fors(container, it, a, b) for(auto it = a; it != b; it++)
using namespace __gnu_pbds;
#define boost ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define MOD 1000000007
#define EPSILON 1e-9
#define PI acos(-1)
#define inf 1e18
#define int long long
#define debug(a) cerr<<#a<<": ";for(auto i:a)cerr<<i<<" ";cerr<<'\n';
#define trace(a) cerr<<#a<<": "<<a<<"\n"
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>


typedef long long  ll;
typedef long double  ldo;
typedef double  db ;
using namespace std;
auto start = std::chrono::system_clock::now();
inline void skj()
{
  std::chrono::time_point<std::chrono::system_clock> end;
  end = std::chrono::system_clock::now();
  std::chrono::duration<double> elapsed_seconds = end - start;
  std::time_t end_time = std::chrono::system_clock::to_time_t(end);
  cerr<<"Time taken " << elapsed_seconds.count()*1000<<"\n";
}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//uniform_int_distribution<int> ud(1, 100); use this for random number generator

    //custom hash for unordered map
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
inline int binexp(int a,int b,int m)
{
    int res=1;
    a%=m;
    while(b)
    {
        if(b&1)
            res=(res*1ll*a)%m;
        a=(a*1ll*a)%m;
        b>>=1;
    }
    return res;
}
const int N = 2505;
int mark[N];
vii g[N];
inline void check(int s, vii &visit) {
    visit[s] = 1;
    for(auto &i : g[s]) {
        if(!visit[i]) {
            check(i, visit);
        }
    }
}
inline void solve_me_senpai() {
   int n, m, p;
    cin >> n >> m >> p;
    vector<pair<pii, int>> edges(m);
    rep(i, m) {
        cin >> edges[i].ff.ff >> edges[i].ff.ss >> edges[i].ss;
        edges[i].ss -= p;
        edges[i].ss *= -1;
        g[edges[i].ff.ff].pb(edges[i].ff.ss);
    }
    forp(i, 1, n) {
        vii visit(n + 1, 0ll);
        check(i, visit);
        mark[i] = visit[n];
    }
    vii dis(n + 1, inf);
    dis[1] = 0;
    rep(i, n - 1) {
        for(auto e : edges) {
            if(mark[e.ff.ss] && dis[e.ff.ff] != inf && dis[e.ff.ss] > dis[e.ff.ff] + e.ss) {
                dis[e.ff.ss] = dis[e.ff.ff] + e.ss;
                //cout << e.ff.ff << " " << e.ff.ss << " " << dis[e.ff.ff] << " " << dis[e.ff.ss] << "\n";
            }
        }
    }
    for(auto e : edges) {
        if(mark[e.ff.ss] && dis[e.ff.ff] != inf && dis[e.ff.ss] > dis[e.ff.ff] + e.ss) {
         //   cout << e.ff.ff << " " << e.ff.ss << "\n";
            o(-1);
            ret;
        }
    }
    o(max(0ll, -dis[n]));
}
signed main()
{
    boost
    int t = 1;
    //cin >> t;
    //int a = 1;
    while(t--) {
        //cout << "Case #" << a  << ": ";
        solve_me_senpai();
        //a++;
    }
    //skj();
    return 0;
}


Measured memory_bytes: 640