from heapq import heappop, heappush
from collections import defaultdict as ddict
p = 10**9+7
N,M = map(int,raw_input().split())
w = map(int,raw_input().split())
w_max = max(w)
E = [[] for i in xrange(N)]
for t in xrange(M):
	i,j = map(lambda x:int(x)-1,raw_input().split())
	E[i].append(j)
C = [[0] for i in xrange(w_max+1)]
C[0].extend([1,0])
for i in xrange(1,w_max+1):
	C[i].extend([(C[i-1][j]+C[i-1][j+1])%p for j in xrange(i+1)]+[0])
F = [ddict(int) for i in xrange(w_max+1)]
for s in xrange(N):
	ws = w[s]
	V = ddict(int)
	Q = []
	heappush(Q,(-w[s],s))
	while Q:
		w_min,h = heappop(Q)
		if w_min >= V[h]: continue
		V[h] = w_min
		if w[h] <= -w_min: F[ws][w[h]] += 1
		w_min = max(w_min,-w[h])
		for nxt in E[h]: heappush(Q,(w_min,nxt))
ans = 0
for wi in xrange(1,w_max+1):
	for wj,v in F[wi].iteritems():
		ans += v*sum(C[wj][k+1]*pow(wj-k,wi,p)*((-1)**(k%2)) for k in xrange(wj)) % p
		ans %= p
print ans