Summa

n = int(input())

ans = 0
seen = set()

for i in range(1, n - 2):
    x = n - i

    for y in range(1, x // 2 + 1):
        z = i - y

        s = set([x, y, z])
        s2 = tuple(sorted([x, y, z]))
        if len(s) != 3:
            continue

        if any(a <= 0 for a in (x, y, z)):
            continue
        
        if x == y or y == z or z == x:
            continue

        if s2 in seen:
            continue


        seen.add(s2)
        ans += 1

print(ans)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: WRONG ANSWER

Test 25

Verdict: WRONG ANSWER

Test 26

Verdict: WRONG ANSWER

Test 27

Verdict: WRONG ANSWER

Test 28

Verdict: WRONG ANSWER