x = int(input())
n = 1
cnt = 1
while x > n:
    cnt += 1
    n = n + 6 * (cnt - 1)
print(cnt)

d7a1bfeba01267115ecca7fb8acf603104049aaf
<mask token>

<mask token>
while x > n:
    cnt += 1
    n = n + 6 * (cnt - 1)
print(cnt)

x = int(input())
n = 1
cnt = 1
while x > n:
    cnt += 1
    n = n + 6 * (cnt - 1)
print(cnt)
