def sum(n, lst):
	cnt = 0
	for i in range(0, n):
		cnt += lst[i]
	return cnt

n = int(raw_input())
c = map(int, raw_input().split())
vote = sum(n, c)
cnt = 0
for i in range(0, n):
	if c[i] <= vote / 10:
		cnt += 1

print cnt * 30