1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<iostream>
 4 #include<algorithm>
 5 #include<vector>
 6 #include<set>
 7 #define be *S.begin()
 8 #define ed *S.rbegin()
 9 #define vv G[i][j].first
10 #define ww G[i][j].second
11 using namespace std;
12 const int N=50010;
13 int k,n,c;
14 vector<pair<int,int> > G[N];
15 set<int> S;
16 int t[N];
17 int main(){
18     #ifndef ONLINE_JUDGE
19         freopen("fs.in","r",stdin);freopen("fs.out","w",stdout);
20     #endif
21     scanf("%d%d%d",&k,&n,&c);
22     while(k--){
23         int u,v,w;
24         scanf("%d%d%d",&u,&v,&w);
25         G[u].push_back(make_pair(v,w));
26     }
27     for(int i=1;i<=n;++i)sort(G[i].begin(),G[i].end());
28     int ans=0,in_car=0;
29     for(int i=1;i<=n;++i){
30         int j=0,j_end=G[i].size();
31         if(!S.empty()&&be==i){
32             ans+=t[be];in_car-=t[be];
33             S.erase(be);
34         }//calc the number of the satisfy cow
35         for(;j<j_end&&in_car<c;++j){
36             int go_into=min(c-in_car,ww);
37             t[vv]+=go_into;in_car+=go_into;ww-=go_into;
38             S.insert(vv);
39             if(in_car==c)break;
40         }//get on the red bus or blablabla,if the bus can be filled,fill it
41         for(;j<j_end&&vv<ed;++j)
42             while(!S.empty()&&ww){
43                 int go_into=min(ww,t[ed]);
44                 t[ed]-=go_into,t[vv]+=go_into;
45                 S.insert(vv);
46                 if(!t[ed])S.erase(ed);
47                 ww-=go_into;
48             }//sacrifice others‘ advantage to get the best advantage
49     }
50     printf("%d\n",ans);
51     return 0;
52 }