#!/usr/bin/env python
import os
import sys
from io import BytesIO, IOBase
from collections import defaultdict
from itertools import *
import random
import math
# MOD = 998244353
MOD = 10**9 + 7
def solve():
N = rint()
if N % 3 == 0:
return N // 3
if N % 3 == 2:
return N // 3 + 1
if N == 4:
return 2
N -= 4
return 2 + N // 3
def main():
T = 1
# T = rint()
for tc in range(1, 1 + T):
ans = solve()
# print(ans)
print(*ans)
# print("Yes" if ans else "No")
# print("YES" if ans else "NO")
# print("Alice" if ans else "Bob")
# print("First" if ans else "Second")
# print("Case #{}: {}".format(tc, ans))
# print(len(ans))
# for row in ans: print(*row)
# region fastio
BUFSIZE = 8192
class FastIO(IOBase):
newlines = 0
def __init__(self, file):
self._file = file
self._fd = file.fileno()
self.buffer = BytesIO()
self.writable = "x" in file.mode or "r" not in file.mode
self.write = self.buffer.write if self.writable else None
def read(self):
while True:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
if not b:
break
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines = 0
return self.buffer.read()
def readline(self):
while self.newlines == 0:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
self.newlines = b.count(b"\n") + (not b)
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines -= 1
return self.buffer.readline()
def flush(self):
if self.writable:
os.write(self._fd, self.buffer.getvalue())
self.buffer.truncate(0), self.buffer.seek(0)
class IOWrapper(IOBase):
def __init__(self, file):
self.buffer = FastIO(file)
self.flush = self.buffer.flush
self.writable = self.buffer.writable
self.write = lambda s: self.buffer.write(s.encode("ascii"))
self.read = lambda: self.buffer.read().decode("ascii")
self.readline = lambda: self.buffer.readline().decode("ascii")
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
rint = lambda: int(input())
def rlist():
return list(map(int, input().split()))
def rgrid(n):
return [rlist() for _ in range(n)]
# endregion
if __name__ == "__main__":
main()