import operator


def accum_dp(xs: list, f, op, e, init: dict, *, is_reset=True):
    dp = init.copy()
    for x in xs:
        pp = {} if is_reset else dp.copy()
        dp, pp = pp, dp
        for fm_key, fm_val in pp.items():
            for to_key, to_val in f(fm_key, fm_val, x):
                dp[to_key] = op(dp.get(to_key, e), to_val)

    return dp


def f(k, v, x):
    # 取る
    nk = (k + x) % 10
    yield nk, v+1

    # 取らない
    yield k, v


N = int(input())
A = list(map(int, input().split()))

init = {0: 0}
dp = accum_dp(A, f, max, 0, init)
ans = dp.get(0, 0)
print(ans)