#include <bits/stdc++.h>
 
//    #include <boost/multiprecision/cpp_int.hpp>
 #define int long long
 #define inf  1000000007
 #define pa pair<int,int>
 #define ll long long
 #define pal pair<double,double>
 #define ppap pair<pa,int>
  #define PI 3.14159265358979323846
  #define paa pair<int,char>
  #define  mp make_pair
  #define  pb push_back
  #define EPS (1e-10)
                                          
    int dx[8]={0,1,0,-1,1,1,-1,-1};
    int dy[8]={1,0,-1,0,-1,1,1,-1};
                                            using namespace std;
                                   			class pa3{
                                            	public:
                                            	int x;
                                   				int y,z;
                                            	pa3(int x=0,int y=0,int z=0):x(x),y(y),z(z) {}
                                            	bool operator < (const pa3 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		 return z<p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                   				bool operator > (const pa3 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		 return z>p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa3 &p) const{
                                            		return x==p.x && y==p.y && z==p.z;
                                            	}
                                            		bool operator != (const pa3 &p) const{
                                            			return !( x==p.x && y==p.y && z==p.z);
                                            	}
                                            
                                            };
                                            
                                            class pa4{
                                            	public:
                                            	int x;
                                            	int y,z,w;
                                            	pa4(int x=0,int y=0,int z=0,int w=0):x(x),y(y),z(z),w(w) {}
                                            	bool operator < (const pa4 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		if(z!=p.z)return z<p.z;
                                            		return w<p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator > (const pa4 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		if(z!=p.z)return z>p.z;
                                            		return w>p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa4 &p) const{
                                            		return x==p.x && y==p.y && z==p.z &&w==p.w;
                                            	}
                                            		
                                            
                                            };
                                            class pa2{
                                            	public:
                                            	int x,y;
                                            	pa2(int x=0,int y=0):x(x),y(y) {}
                                            	pa2 operator + (pa2 p) {return pa2(x+p.x,y+p.y);}
                                            	pa2 operator - (pa2 p) {return pa2(x-p.x,y-p.y);}
                                            	bool operator < (const pa2 &p) const{
                                            		return y != p.y ? y<p.y: x<p.x;
                                            	}
                                            	bool operator > (const pa2 &p) const{
                                            		return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa2 &p) const{
                                            		return abs(x-p.x)==0 && abs(y-p.y)==0;
                                            	}
                                            	bool operator != (const pa2 &p) const{
                                            		return !(abs(x-p.x)==0 && abs(y-p.y)==0);
                                            	}
                                            		
                                            
                                            };
                                            
 
                      
                                string itos( int i ) {
                                ostringstream s ;
                                s << i ;
                                return s.str() ;
                                }
                                 
                                int gcd(int v,int b){
                                	if(v>b) return gcd(b,v);
                                	if(v==b) return b;
                                	if(b%v==0) return v;
                                	return gcd(v,b%v);
                                }
                 
                            
                                int mod;
int extgcd(int a, int b, int &x, int &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    int d = extgcd(b, a%b, y, x);
    y -= a/b * x;
    return d;
}
pa operator+(const pa & l,const pa & r) {   
    return {l.first+r.first,l.second+r.second};                                    
}    
pa operator-(const pa & l,const pa & r) {   
    return {l.first-r.first,l.second-r.second};                                    
}  
                                
                int pr[200010];
                int inv[200010];
                
                int beki(int wa,int rr,int warukazu){
                	if(rr==0) return 1%warukazu;
                	if(rr==1) return wa%warukazu;
                	wa%=warukazu;
                	if(rr%2==1) return ((ll)beki(wa,rr-1,warukazu)*(ll)wa)%warukazu;
                	ll zx=beki(wa,rr/2,warukazu);
                	return (zx*zx)%warukazu;
                }
 
                
    			int comb(int nn,int rr){
    				if(rr<0 || rr>nn || nn<0) return 0;
    				int r=pr[nn]*inv[rr];
    				r%=mod;
    				r*=inv[nn-rr];
    				r%=mod;
    				return r;
    			}
                
                void gya(int ert){
                	pr[0]=1;
                	for(int i=1;i<=ert;i++){
                		pr[i]=(pr[i-1]*i)%mod;
                	}
                		inv[ert]=beki(pr[ert],mod-2,mod);
                	for(int i=ert-1;i>=0;i--){
                		inv[i]=inv[i+1]*(i+1)%mod;
                	}
                }
                
              //   cin.tie(0);
    		//	ios::sync_with_stdio(false);
    			//priority_queue<pa3,vector<pa3>,greater<pa3>> pq;            
                 //sort(ve.begin(),ve.end(),greater<int>());
//    mt19937(clock_per_sec);
  //  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()) ;
      
       
       
                               //----------------kokomade tenpure------------


int dp[2510][2];
vector<pa3> V,V2;
vector<int> G[2600],G2[2600];

bool vis1[3600],vis2[2600];

void dfs1(int r){
	if(vis1[r])return;
	vis1[r]=1;
	for(auto v:G[r])dfs1(v);
}
void dfs2(int r){
	if(vis2[r])return;
	vis2[r]=1;
	for(auto v:G2[r])dfs2(v);

}

int sai[2600]={},si[2600]={};
int dp2[23000][2700];

 signed main(){
 	
 
    cin.tie(0);
	ios::sync_with_stdio(false);
	
	int n,m,p;
 	cin>>n>>m>>p;
 	

 	
 	for(int i=0;i<m;i++){
 		int y,yy,yyy;
 		cin>>y>>yy>>yyy;
 		yyy-=p;
 		G[y].pb(yy);
 		G2[yy].pb(y);
 			V.pb({y,yy,yyy});
 	}
 	dfs1(1);
 	dfs2(n);
 	for(int i=1;i<=n;i++)dp[i][0]=-inf*1000000ll;
 	dp[1][0]=0;
 	vector<int> ans;
 	ans.pb(-1);
 	/*
 	for(int i=1;i<=n;i++)cout<<vis1[i]<<" ";
 	cout<<endl;
 	for(int i=1;i<=n;i++)cout<<vis2[i]<<" ";
 	cout<<endl;
 	*/
 	for(auto v:V){
 			if(vis1[v.x]==0 ||vis1[v.y]==0||vis2[v.x]==0 ||vis2[v.y]==0)continue;
 		V2.pb(v);
 	}
 	
 	for(int i=1;i<=22999;i++){
 		for(int j=1;j<=n;j++)dp2[i][j]=dp2[i-1][j];
 		for(auto v:V2){
 			if(dp2[i][v.y]<dp2[i-1][v.x]+v.z && i>=10020){
 				cout<<-1<<endl;
 				return 0;
 			}
 			dp2[i][v.y]=max(dp2[i][v.y],dp2[i-1][v.x]+v.z);
 		}
 	}
 	
 	
 	int ww=0;
 	for(int i=1;i<=20000;i++){
 		for(int j=1;j<=n;j++)dp[j][i%2]=-inf*1000000ll;
 
 		for(auto v:V2){
 			
 			if(dp[v.x][1-i%2]>-inf*1000000ll){

 				dp[v.y][i%2]=max(dp[v.y][i%2],dp[v.x][1-i%2]+v.z);
 			}
 		}
 		

 		
 		//if(i<100)cout<<dp[n][i%2]<<endl;
 		ww=max(ww,dp[n][i%2]);
 	}
 	
 	cout<<ww<<endl;
 	return 0;
 	int an=0;
 int it=-1;
 	for(int i=0;i<=20000;i++){
 		if(an<ans[i]){
 					an=max(an,ans[i]);
 it=i;
 		}
 	}
 	
 	
 	 cout<<an<<endl;
 	
 	
	return 0;

 	
 	
 }

Measured memory_bytes: 488320