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)
C = [[0]*(i+1) for i in xrange(w_max+1)]
C[0][0] = 1
for i in xrange(w_max):
	for j in xrange(i+1):
		C[i+1][j] += C[i][j]; C[i+1][j] %= p
		C[i+1][j+1] += C[i][j]; C[i+1][j+1] %= p
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)
proj = set()
for s in xrange(N):
	visited = ddict(int)
	Q = []
	heappush(Q,(-w[s],s))
	while Q:
		w_min,h = heappop(Q)
		w_min *= -1
		if w_min <= visited[h]: continue
		visited[h] = w_min
		if w[s] >= w[h] and w[h] <= w_min:
			proj.add((s,h))
		w_min = min(w_min,w[h])
		for nxt in E[h]: heappush(Q,(-w_min,nxt))
ans = 0
for i,j in proj:
	wi = w[i]; wj = w[j]
	ans += sum(C[wj][k]*pow(wj-k,wi,p)*((-1)**(k%2)) for k in xrange(wj))
	ans %= p
print ans