n, m = map(int, input().split())
nums = [0] + list(map(int, input().split()))
graph = [[] for _ in range(n + 1)]
for _ in range(m):
    x, y = map(int, input().split())
    graph[x].append(y)
count = 0
for i in range(1, n + 1):
    if graph[i]:
        avg = sum(nums[x] for x in graph[i]) / len(graph[i])
        if nums[i] < avg:
            count += 1
print(count)