n = int(input())
a = list(map(int,input().split()))
a.sort()
i = 0
s = 0
ans = [0]
while True:
  if i == n-1:
    break
  else:
    s += a[i]
    if s % 10 == 0:
      ans.append(i)
    else:
      i += 1
print(max(ans))