#include <bits/stdc++.h>
using namespace std;

#define fs first
#define sc second
#define pb emplace_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()

const int32_t inf = 1001001001;
const int64_t infll = 1001001001001001001ll;
const int dx[] = {0, -1, 1, 0, -1, 1, -1, 1}, dy[] = {-1, 0, 0, 1, -1, -1, 1, 1};

template <typename T> using vector2d = vector<vector<T>>;

// clang-format off
template <typename T> void sort(vector<T> &v) { sort(all(v)); }
ostream &operator<<(ostream &os, __int128_t value) { if (ostream::sentry(os)) { __uint128_t tmp = value < 0 ? -value : value; char buffer[64]; char *d = end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (value < 0) { --d; *d = '-'; } int len = end(buffer) - d; if (os.rdbuf()->sputn(d, len) != len) { os.setstate(ios_base::badbit); }} return os; }
istream &operator>>(istream &is, __int128_t &value) { string in; is >> in; value = 0; for (const char &c : in) { if ('0' <= c && c <= '9') value = 10 * value + (c - '0'); } if (in[0] == '-') value *= -1; return is; }
ostream &operator<<(ostream &os, __uint128_t value) { if (ostream::sentry(os)) { char buffer[64]; char *d = end(buffer); do { --d; *d = "0123456789"[value % 10]; value /= 10; } while (value != 0); int len = end(buffer) - d; if (os.rdbuf()->sputn(d, len) != len) { os.setstate(ios_base::badbit); }} return os; }
istream &operator>>(istream &is, __uint128_t &value) { string in; is >> in; value = 0; for (const char &c : in) { if ('0' <= c && c <= '9') value = 10 * value + (c - '0'); } return is; }
template <typename T> ostream &operator<<(ostream &os, vector<T> &v) { os << v[0]; for (int i = 1; i < v.size(); ++i) os << " " << v[i]; return os; }
template <typename T> istream &operator>>(istream &is, vector<T> &v) { for (T &in : v) is >> in; return is; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, pair<T1, T2> p) { os << p.fs << " " << p.sc; return os; }
template <typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p) { is >> p.fs >> p.sc; return is; }

struct IoSetup { IoSetup(){ cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup;

inline int64_t in() { int64_t x = 0; cin >> x; return x; }
template <typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template <typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
// clang-format on

struct BellmanFord {
  BellmanFord() {}
  BellmanFord(int n) {
    init(n);
  }

  struct edge {
    edge() {}
    edge(int to, int64_t cost) : to(to), cost(cost) {}

    int to;
    int64_t cost;
  };

  const int64_t linf = 1001001001001001001ll;

  bool NC;
  vector<vector<edge>> G;
  vector<int64_t> d;

  void init(int n) {
    NC = false;
    G.resize(n);
  }

  void add_edge(int u, int v, int64_t c) {
    G[u].push_back(edge(v, c));
  }

  void build(int s) {
    d = vector<int64_t>(G.size(), linf);
    d[s] = 0;

    for (int i = 0; i < G.size(); ++i) {
      for (int v = 0; v < G.size(); ++v) {
        for (auto &e : G[v]) {
          if (d[v] != linf && d[e.to] > d[v] + e.cost) {
            d[e.to] = d[v] + e.cost;
            if (i == G.size() - 1 && e.to == G.size() - 1) NC = true;
          }
        }
      }
    }
  }

  void build() {
    build(0);
  }

  // int64_t dist(int v) {
  //   return d[v];
  // }

  void ans() {
    if (NC)
      cout << "inf" << endl;
    else
      cout << -d.back() << endl;
  }
};

signed main(int argc, char *argv[]) {
  int n = in(), m = in();

  BellmanFord G(n);
  for (int i = 0; i < m; ++i) {
    int a = in() - 1, b = in() - 1, c = in();
    G.add_edge(a, b, -c);
  }
  G.build();
  G.ans();
}


Measured memory_bytes: 384