N = int(input())
A = list(map(int, input().split()))
dp = [-100]*10
dp[0] = 0
for i in range(N):
  new_dp = [0]*10
  for j in range(10):
    new_dp[j] = max(dp[j],dp[(j-A[i])%10]+1)
  dp = new_dp
print(dp[0])