import sys
sys.setrecursionlimit(1000000)
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][j] %= p
		C[i+1][j] += C[i][j]
		C[i+1][j+1] += C[i][j]
for i in xrange(w_max+1): C[w_max][i] %= 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()
visited = set()
def dfs(s,h,w_min):
	if h in visited: return
	visited.add(h)
	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]:
		dfs(s,nxt,w_min)
for i in xrange(N):
	visited = set()
	dfs(i,i,w[i])
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