#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
#define valid(y,x,h,w) (0<=y&&y<h&&0<=x&&x<w)
#define tpl(...) make_tuple(__VA_ARGS__)
const int INF = 0x3f3f3f3f;
const double EPS = 1e-8;
const double PI = acos(-1);
typedef long long ll;
typedef pair<int,int> pii;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class T>ostream&operator<<(ostream &o,const vector<T>&t){o<<'[';FOR(i,t){if(i!=t.begin())o<<',';o<<*i;}return o<<']';}
template<class S,class T>ostream&operator<<(ostream &o,const pair<S,T>&t){return o<<'('<<t.first<<','<<t.second<<')';}
template<int N,class Tp>void output(ostream&,const Tp&){}
template<int N,class Tp,class,class ...Ts>void output(ostream &o,const Tp&t){if(N)o<<',';o<<get<N>(t);output<N+1,Tp,Ts...>(o,t);}
template<class ...Ts>ostream&operator<<(ostream&o,const tuple<Ts...>&t){o<<'(';output<0,tuple<Ts...>,Ts...>(o,t);return o<<')';}
template<class T>void output(T t,char z=10){if(t<0)t=-t,putchar(45);int c[20];
int k=0;while(t)c[k++]=t%10,t/=10;for(k||(c[k++]=0);k;)putchar(c[--k]^48);putchar(z);}
template<class T>void outputs(T t){output(t);}
template<class S,class ...T>void outputs(S a,T...t){output(a,32);outputs(t...);}
template<class T>void output(T *a,int n){REP(i,n)output(a[i],i!=n-1?',':10);}
template<class T>void output(T *a,int n,int m){REP(i,n)output(a[i],m);}
template<class T>bool input(T &t){int n=1,c;for(t=0;!isdigit(c=getchar())&&~c&&c-45;);
if(!~c)return 0;for(c-45&&(n=0,t=c^48);isdigit(c=getchar());)t=10*t+c-48;t=n?-t:t;return 1;}
template<class S,class ...T>bool input(S&a,T&...t){input(a);return input(t...);}

typedef int Weight;
struct Edge {
  int src, dst;
  Weight weight;
  Edge(int src, int dst, Weight weight) :
    src(src), dst(dst), weight(weight) { }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

vector<int> tsort(const Graph &g) {
  int n = g.size();
  vector<int> num(n);
  REP(i, n) FOR(e, g[i]) num[e->dst]++;
  queue<int> Q;
  REP(i, n) if (num[i] == 0) Q.push(i);
  vector<int> res;
  while(!Q.empty()) {
    int v = Q.front(); Q.pop();
    res.push_back(v);
    FOR(e, g[v]) {
      if (num[e->dst]) {
        num[e->dst]--;
        if (num[e->dst] == 0) Q.push(e->dst);
      }
    }
  }
  REP(i, n) if (num[i]) return vector<int>();
  return res;
}
int dp[100000][101];
int main() {
  int n,m,w;
  while(input(n,m,w)) {
    Graph g(n);
    REP(i,m) {
      int s,t,c;
      input(s,t,c);
      g[s].push_back(Edge(s,t,c));
    }
    vector<int> order = tsort(g);
    memset(dp,0,sizeof(dp));
    // REP(i,n) dp[i][0] = 1;
    REP(i,n) {
      int id = order[i];
//      cout << id << endl;
      FOR(it, g[id]) {
        REP(j,101) {
          if (j+it->weight > 100) break;
          dp[it->dst][j+it->weight] |= dp[it->src][j];
          if (j == 0)
            dp[it->dst][j+it->weight] |= 1;
        }
      }
    }
    int ans = -INF;
    REP(i,n) {
      REP(j,101) {
        if (dp[i][j] && j+w<0) {
          chmax(ans, j+w);
        }
      }
    }
    if (ans == -INF) cout << "NA" << endl;
    else cout << ans << endl;
  }
}
