#include <bits/stdc++.h> using namespace std; using ll = long long; const ll INF2 = 1ll << 60; vector<ll> Bellman_Ford(vector<vector<pair<ll,ll>>> &graph,int start){ int n=graph.size(),x; vector<ll> dist(n,INF2); queue<int> next; dist[start]=0; int cnt=n-1; while(cnt--){ for(int i=0;i<n;i++){ if(dist[i]==INF2)continue; for(int j=0;j<graph[i].size();j++){ if(dist[i]+graph[i][j].second<dist[graph[i][j].first]){ dist[graph[i][j].first]=dist[i]+graph[i][j].second; } } } } for(int i=0;i<n;i++){ if(dist[i]==INF2)continue; for(int j=0;j<graph[i].size();j++){ if(dist[graph[i][j].first]!=-INF2&& dist[i]+graph[i][j].second<dist[graph[i][j].first]){ dist[graph[i][j].first]=-INF2; next.push(graph[i][j].first); } } } while(!next.empty()){ x=next.front(); next.pop(); for(int j=0;j<graph[x].size();j++){ if(dist[graph[x][j].first]!=-INF2){ dist[graph[x][j].first]=-INF2; next.push(graph[x][j].first); } } } return dist; } int main(){ ios::sync_with_stdio(false); cin.tie(0); int n, m, v, u, c; cin >> n >> m; vector<vector<pair<ll,ll>>> g(2 * n); for(int i = 0; i < n; i++){ cin >> c; g[i].emplace_back(i + n, -c); } for(int i = 0; i < m; i++){ cin >> u >> v >> c; g[--u + n].emplace_back(--v, c); } auto dp = Bellman_Ford(g, 0); ll ans = dp.back(); if(ans == -INF2){ cout << "inf\n"; }else{ cout << -ans << '\n'; } }