Omenat

import collections
n = int(input())
p = (map(int, input().split()))

q = collections.Counter(map(lambda x: x % 3, p))
total = 0
a0 = q.get(0) or 0
a1 = q.get(1) or 0
a2 = q.get(2) or 0
# print(a0, a1, a2)
total += a0
if a1 < a2:
    a2 -= a1
    total += a1 * 2
    a1 = 0
    total += 3 * (a2 // 3)
else:
    a1 -= a2
    total += a2 * 2
    a2 = 0
    total += 3 * (a1 // 3)
# a = min(a1, a2)
# total += a * 2
# a1 -= a
# a2 -= a
# total

print(total)

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: WRONG ANSWER

Test 6

Group: 1

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: WRONG ANSWER

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: WRONG ANSWER

Test 18

Group: 3

Verdict: ACCEPTED