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

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto &&e : v)
#define all(a) begin(a), end(a)
#define sz(a) (ssize(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S> bool chmin(T &a, const S &b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S> bool chmax(T &a, const S &b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;

int main() {
  int N, M;
  cin >> N >> M;
  using al3 = array<ll, 3>;
  vector<al3> E(N + M);
  rep(i, N) {
    int A;
    cin >> A;
    E[i] = al3{i, i + N, -A};
  }
  rep(i, M) {
    auto &x = E[i + N];
    cin >> x[0] >> x[1] >> x[2];
    x[0] += N - 1;
    x[1] -= 1;
  }
  vl dist(N * 2, INFL);
  dist[0] = 0;
  rep(i, N * 2) {
    for (auto [u, v, c] : E) {
      if (dist[u] != INFL)
        chmin(dist[v], dist[u] + c);
    }
  }
  bool inf = 0;
  for (auto [u, v, c] : E) {
    if (dist[u] != INFL && chmin(dist[v], dist[u] + c))
      inf = 1;
  }
  if (inf)
    cout << "inf\n";
  else
    cout << -dist[N * 2 - 1] << '\n';
}