#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef complex<double> P;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define REP(i,n) for(ll i=0;i<n;++i)
#define REPR(i,n) for(ll i=1;i<n;++i)
#define FOR(i,a,b) for(ll i=a;i<b;++i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define MOD (ll)(1e9+7)
#define ADD(a,b) a=((a)+(b))%MOD
#define FIX(a) ((a)%MOD+MOD)%MOD

ll inv(ll x){
  ll t = MOD-2;
  ll r = 1;
  while(t){
    if(t&1)r=r*x%MOD;
    x=x*x%MOD;
    t>>=1;
  }
  return r;
}

ll mypow(ll a,ll x){
  if(x==0)return 1;
  ll p = mypow(a,x/2);
  p = p*p%MOD;
  if(x&1) p = p*a%MOD;
  return p;
}

ll fact[1000];

ll comb(ll a,ll b){
  if(a-b<0)return 0;
  return fact[a]*inv(fact[a-b])%MOD*inv(fact[b])%MOD;
}

ll zensha(ll n,ll k){
  ll ret = 0;
  REPR(i,k+1){
    ll tmp = 1;
    if((k-i)%2==1)tmp = MOD-1;
    tmp = tmp*comb(k,i)%MOD;
    tmp = tmp*mypow(i,n)%MOD;
    ret = (ret+tmp)%MOD;
  }
  return ret;
}

int main(){
  fact[0] = 1;
  REPR(i,1000) fact[i] = fact[i-1]*i%MOD;

  ll n,m;
  cin>>n>>m;
  vl w(n);
  REP(i,n) cin>>w[i];
  vl G[n];
  REP(i,m){
    ll x,y;
    cin>>x>>y;
    --x;--y;
    if(x==y)continue;
    G[x].push_back(y);
  }
  ll result = 0;
  REP(src,n){
    vl flow(n,0);
    flow[src] = w[src];
    priority_queue<pll> Q;
    Q.push(make_pair(flow[src],src));
    vector<bool> used(n,false);
    while(!Q.empty()){
      pll P = Q.top(); Q.pop();
      ll f = P.first;
      ll u = P.second;
      if(used[u])continue;
      used[u] = true;
      REP(ed,G[u].size()){
        ll v = G[u][ed];
        if(flow[v]>=min(f,w[v]))continue;
        flow[v]=min(f,w[v]);
        Q.push(make_pair(flow[v],v));
      }
    }
    REP(to,n){
      if(flow[to]==w[to]){
        result += zensha(w[src],w[to]);
        result %= MOD;
      }
    }
  }
  cout << result << endl;
  return 0;
}