Problem:
 Score : 100 points    Problem Statement There are N students in a school.  We will divide these students into some groups, and in each group they will discuss some themes.  You think that groups consisting of two or less students cannot have an effective discussion, so you want to have as many groups consisting of three or more students as possible.  Divide the students so that the number of groups consisting of three or more students is maximized.      Constraints  1 \leq N \leq 1000  All input values are integers.         Input Input is given from Standard Input in the following format:  N       Output If you can form at most x groups consisting of three or more students, print x .        Sample Input 1 8      Sample Output 1 2  For example, you can form a group of three students and another of five students.       Sample Input 2 2      Sample Output 2 0  Sometimes you cannot form any group consisting of three or more students, regardless of how you divide the students.       Sample Input 3 9      Sample Output 3 3

Solution (Python):
N=int(input())
print(N//3)

Solution (Python):


a = int(input())

print(int(a/3))

Solution (Python):

n = int(input())

print(n//3)

Solution (Python):
N=int(input())
print(N//3)

Solution (Python):
N = int(input())
print(N//3)

Solution (Python):
N=int(input())
g=N//3
print(g)

Solution (Python):
n = int(input())

print(n//3)

Solution (Python):
print(int(input()) // 3)

Solution (Python):
print input()/3

Solution (Python):
n = int(input())
if n < 3:
    print(0)
else:
    print(n // 3)

Solution (Python):
n = int(input())

print(int(n/3))

Solution (Python):
n = int(input())

def solve():
    print(n//3)
solve()

Solution (Python):


import os
import sys
import math
import numpy as np


N = int(input())

print(int(N/3))

Solution (Python):
print input()/3

Solution (Python):
n=int(input())

print(n//3)

Solution (Python):
N=int(input())
print(int(N/3))

Solution (Python):
N = int(input())

print(int(N / 3))

Solution (Python):
N = int(input())
print(int(N/3))

Solution (Python):
N = int(input())
print(int(N / 3))

Solution (Python):



import array
from bisect import *
from collections import *
import fractions
import heapq 
from itertools import *
import math
import random
import re
import string

N = int(input())
ans = 0
while N > 0:
    if N >= 6:
        ans += 1
        N -= 3
    elif N >= 3:
        ans += 1
        N = 0
    else:
        N = 0
print(ans)

Solution (Python):
import sys,collections;sys.setrecursionlimit(10**7)
def Is(): return [int(x) for x in sys.stdin.readline().split()]
def Ss(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def S(): return input()

n = I()
print(n//3)

Solution (Python):
print(int(input())//3)

Solution (Python):
N = int(input())

print(N//3)

Solution (Python):
n = int(input())

res = n // 3
print(res)

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())
print(n//3)

Solution (Python):
N = int(input())
group = int(N / 3)
print(group)

Solution (Python):
def main():
    N = int(input())
    print(int(N/3))


if __name__ == '__main__':
    main()

Solution (Python):
N = int(input())

print(int(N / 3))

Solution (Python):
n=int(input())
print(int(n/3))

Solution (Python):
n = int(input())
print(n // 3)

Solution (Python):
N = int(input())

print(N // 3)

Solution (Python):
N = int(input())
print(N // 3)

Solution (Python):
N=int(input())
print(N//3)

Solution (Python):
def main():
    n = int(input())
    print(n // 3)

if __name__ == '__main__':
    main()

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())

print(n // 3)

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())
x = n // 3
print(int(x))

Solution (Python):
N = int(input())
a = N // 3
print(a)

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())
print(int(n/3))

Solution (Python):
n=int(input())
print(n//3)

Solution (Python):
def main():
    N = int(input())

    ans = N // 3
    print(ans)


if __name__ == '__main__':
    main()

Solution (Python):

n = int(input()) 
print(n//3)

Solution (Python):
a = int(input().strip())
print(a // 3)

Solution (Python):
def i1():
 return int(input())
def i2():
 return [int(i) for i in input().split()]
print(i1()//3)

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())
print(n // 3)

Solution (Python):

"""
A - Grouping 2
https://beta.atcoder.jp/contests/abc089/tasks/abc089_a

"""
import sys
from sys import stdin
input = stdin.readline


def main(args):
    N = int(input())
    print(N//3)


if __name__ == '__main__':
    main(sys.argv[1:])

Solution (Python):
N =int(input())
print(N//3)

Solution (Python):
n = int(input())
print(n//3)

Solution (Python):

a = int(input())







ans = a//3



print(ans)

Solution (Python):
print(int(int(input())/3))

Solution (Python):
N = int(input())
print(N//3)

Solution (Python):
N = int(input())
print(N // 3)

Solution (Python):
import sys
N=int(input())
print(N//3)

Solution (Python):
n = int(input())
print(n // 3)

Solution (Python):
print(int(input())//3)

Solution (Python):
n=int(input())
print(n//3)

Solution (Python):
print (lambda x:x/3)(input())

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(raw_input())
print n/3

Solution (Python):
N = int(input())

print(N // 3)

Solution (Python):
N = int(input())
print(N // 3)

Solution (Python):

import math

M = int(input())

print(M//3)

Solution (Python):
n = int(input())

print(n // 3)

Solution (Python):
N = int(input())
print(N//3)

Solution (Python):
N=int(input())
print(N//3)

Solution (Python):
N = int(input())
print(N // 3)

Solution (Python):
print(int(input())//3)

Solution (Python):
N=int(input())
print(N//3)

Solution (Python):
n = int(input())

print(n //3)

Solution (Python):
n = int(input())
print(n//3)

Solution (Python):
N= int(input())
print(N//3)

Solution (Python):
print(int(input())//3)

Solution (Python):
n = int(input())
print(n // 3)

Solution (Python):
print(int(input())//3)

Solution (Python):
print int(raw_input())//3

Solution (Python):
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**15
mod = 10**9+7

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)


def main():
    n = I()

    return n // 3


print(main())

Solution (Python):
print(int(input())//3)

Solution (Python):
a = int(input())
print(a // 3)

Solution (Python):
import sys

stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline()

print(ni()//3)