1779

//   __________________
//  | ________________ |
//  ||          ____  ||
//  ||   /\    |      ||
//  ||  /__\   |      ||
//  || /    \  |____  ||
//  ||________________||
//  |__________________|
//  \###################\
//   \###################\
//    \        ____       \
//     \_______\___\_______\
// An AC a day keeps the doctor away.

#pragma g++ optimize("Ofast")
#pragma loop_opt(on)
#include <bits/extc++.h>
#ifdef local
#define debug(x) (cerr<<#x<<" = "<<(x)<<'\n')
#else
#include <bits/stdc++.h>
#define debug(x) ((void)0)
#endif // local
#define all(v) begin(v),end(v)
#define siz(v) (ll(v.size()))
#define get_pos(v,x) (lower_bound(all(v),x)-begin(v))
#define sort_uni(v) sort(begin(v),end(v)),v.erase(unique(begin(v),end(v)),end(v))
#define pb emplace_back
#define ff first
#define ss second
#define mem(v,x) memset((v),(x),sizeof(v))

using namespace std;
using namespace __gnu_pbds;
typedef int64_t ll;
typedef long double ld;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pld;
template <typename T> using max_heap = std::priority_queue<T,vector<T>,less<T> >;
template <typename T> using min_heap = std::priority_queue<T,vector<T>,greater<T> >;
template <typename T> using rbt = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
constexpr ld PI = acos(-1), eps = 1e-7;
constexpr ll N = 120025, INF = 1e18, MOD = 998244353, K = 20, inf = 1e9;
constexpr inline ll cdiv(ll x, ll m) { return x/m + ((x<0 ^ m>0) && (x%m)); } // ceiling divide
constexpr inline ll modpow(ll e,ll p,ll m=MOD) {ll r=1; for(e%=m;p;p>>=1,e=e*e%m) if(p&1) r=r*e%m; return r;}

struct Dinic {
    struct Edge {
        int rest, to;
    } E[N];
    vector<int> G[N];
    int n, tot, dis[N], cur[N];
    void init(int _n) {
        n = _n;
        for(int i = 0; i < n; i++) G[i].clear();
        tot = 0;
    }
    void addEdge(int a, int b, int cap) {
        E[tot] = {cap, b}, G[a].pb(tot++);
        E[tot] = {0, a}, G[b].pb(tot++);
    }
    bool BFS(int s, int t) {
        for(int i = 0; i < n; i++) dis[i] = -1;
        queue<int> q;
        dis[s] = 0;
        q.push(s);
        while(!q.empty()) {
            int i = q.front(); q.pop();
            for(int id: G[i]) if(E[id].rest && dis[E[id].to] == -1) {
                dis[E[id].to] = dis[i] + 1;
                q.push(E[id].to);
            }
        }
        return dis[t] != -1;
    }
    int DFS(int i, int t, int lim) {
        if(i == t) return lim;
        int ans = 0;
        while(cur[i] < G[i].size() && lim) {
            int id = G[i][cur[i]++];
            if(dis[E[id].to] != dis[i]+1) continue;
            int f = DFS(E[id].to, t, min(lim, E[id].rest));
            E[id].rest -= f;
            E[id^1].rest += f;
            ans += f;
            lim -= f;
        }
        return ans;
    }
    int maxFlow(int s, int t) {
        int ans = 0;
        while(BFS(s,t)) {
            for(int i = 0; i < n; i++) cur[i] = 0;
            while(int f = DFS(s,t,inf)) ans += f;
        }
        return ans;
    }
} flow;
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    int n, m;
    cin >> n >> m;
    flow.init(n+2);
    int sum = 0;
    for(int i = 1, v; i <= n; i++) {
        cin >> v;
        if(v >= 0)
            flow.addEdge(0, i, v), sum += v;
        else
            flow.addEdge(i, n+1, -v);
    }
    while(m--) {
        int a, b;
        cin >> a >> b;
        flow.addEdge(b, a, inf);
    }
    cout << sum - flow.maxFlow(0, n+1) << '\n';
}