#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

using Edge = tuple<ll, int, int>;
pair<vector<ll>, vector<ll>> bellman_ford(int V, int st, vector<Edge> &edges){
    vector<ll> dist(V, LINF), negative(V, false);
    dist[st] = 0;
    for(int i = 0; i < V - 1; i++){
        bool update = false;
        for(auto &e : edges){
            ll weight;
            int now, nxt;
            tie(weight, now, nxt) = e;
            if(dist[now] != LINF && dist[nxt] > dist[now] + weight){
                dist[nxt] = dist[now] + weight;
                update = true;
            }
        }
        if(!update)return make_pair(dist, negative);
    }

    for(int i = 0; i < V; i++){
        for(auto &e : edges){
            ll weight;
            int now, nxt;
            tie(weight, now, nxt) = e;
            if(dist[now] != LINF && dist[nxt] > dist[now] + weight){
                dist[nxt] = dist[now] + weight;
                negative[nxt] = true;
            }
            if(negative[now]) negative[nxt] = true;
        }
    }

    return make_pair(dist, negative);
}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int N, M; cin >> N >> M;
    vector<ll> A(N);
    rep(i,N) cin >> A[i];

    vector<Edge> edges;
    rep(i,N) {
        edges.push_back(Edge{-A[i], i, i + N});
    }
    rep(i,M){
        int a, b, c; cin >> a >> b >> c;
        a--, b--;
        edges.push_back(Edge{c, a + N, b});
    }

    auto ret = bellman_ford(2 * N, 0, edges);
    debug(ret.first);
    debug(ret.second);
    if(!ret.second[2 * N - 1]){
        cout << -ret.first[2 * N - 1] << endl;
    }
    else{
        cout << "inf" << endl;
    }
}