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):


import sys






























def main():
    mod = 1000000007                
    inf = float('inf')              
    
    sys.setrecursionlimit(10**6)    
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())
    
    
    n = ii()
    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):
a=int(input())
print(a//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):
import math
n = int(input())
print(math.floor(n / 3))

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())
print(n // 3)

Solution (Python):
from math import floor
print(floor(int(input()) / 3))

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

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

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

Solution (Python):
import collections


def inputStrOnebyOne():
    s = list(input())
    return s


def inputOnebyOne_Int():
    a = list(int(x) for x in input().split())
    return a

def main():
    a = int(input())
    print(int(a/3))

if __name__=='__main__':
    main()

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

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

print(n // 3)

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

input = sys.stdin.readline


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


if __name__ == "__main__":
    main()

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):

"""
Created on Fri May 15 13:51:13 2020

@author: shinba
"""

print(int(input())//3)

Solution (Python):

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

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

Solution (Python):
print(int(input())//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):
import math
N = int(input())
print(math.floor(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):
import sys
import math
import bisect

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

if __name__ == "__main__":
    main()

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

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

Solution (Python):

def resolve():
	n = int(input())
	print(n//3)
resolve()

Solution (Python):

import sys
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
input=lambda: sys.stdin.readline().rstrip()
YesNo=lambda b: bool([print('Yes')] if b else print('No'))
YESNO=lambda b: bool([print('YES')] if b else print('NO'))
int1=lambda x:int(x)-1

def main():
    print(int(input())//3)

if __name__ == '__main__':
    main()

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

Solution (Python):

n = int(input())
print(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())

ans = n // 3
print(ans)

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

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

if n >= 3:
    group = n//3
else:
    group = 0
print(group)

Solution (Python):
def ABC_89_A():
    N = int(input())
    if N>=3:
        print(int(N/3))
    else:
        print(0)

if __name__ == '__main__':

    ABC_89_A()

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

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

if __name__ == '__main__':
    main()

Solution (Python):
def main():
    n = int(input())
    if n < 3: print(0)
    elif n == 3: print(1)
    else: print(n//3)

if __name__ == '__main__':
    main()

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):

import sys
import math
from bisect import bisect_left, bisect_right, insort_left, insort_right
from collections import defaultdict, deque, Counter
from copy import deepcopy
from fractions import gcd
from functools import lru_cache, reduce
from heapq import heappop, heappush
from itertools import accumulate, groupby, product, permutations, combinations, combinations_with_replacement
from math import ceil, floor, factorial, log, sqrt, sin, cos
from operator import itemgetter
from string import ascii_lowercase, ascii_uppercase, digits
sys.setrecursionlimit(10**7)
rs = lambda: sys.stdin.readline().rstrip()
ri = lambda: int(rs())
rf = lambda: float(rs())
rs_ = lambda: [_ for _ in rs().split()]
ri_ = lambda: [int(_) for _ in rs().split()]
rf_ = lambda: [float(_) for _ in rs().split()]
INF = float('inf')
MOD = 10 ** 9 + 7
PI = math.pi

N = ri()
print(N // 3)

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

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

if n < 3:
    print(0)
else:
    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):
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())
if N%3 < 3:
  print(N//3)
elif N<3:
  print('0')
else:
  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):
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):
print( int(input()) // 3)

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

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

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

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

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

Solution (Python):
import sys
import itertools
sys.setrecursionlimit(1000000000)
from heapq import heapify,heappop,heappush,heappushpop

import collections

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

Solution (Python):
import math
n = int(input())
print(math.floor(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):
N = int(input())
print(N//3)

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

print(n//3)

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

Solution (Python):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import accumulate, permutations, combinations, product, groupby
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from fractions import gcd
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

N = INT()
print(N//3)

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

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

Solution (Python):
def I(): return int(input())
def MI(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def LI2(): return [int(input()) for i in range(n)]
def MXI(): return [LI()for i in range(n)]
inf = 10**17
mod = 10**9 + 7

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

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

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

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


if __name__ == '__main__':
    main()

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

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

Solution (Python):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import accumulate, permutations, combinations, product
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from fractions import gcd
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

N = INT()
num = 3
cnt = 0
print(N // 3)

Solution (Python):
import sys
sys.setrecursionlimit(1 << 25)
read = sys.stdin.readline
ra = range
enu = enumerate


def read_ints():
    return list(map(int, read().split()))


def read_a_int():
    return int(read())


def read_tuple(H):
    '''
    H is number of rows
    '''
    ret = []
    for _ in range(H):
        ret.append(tuple(map(int, read().split())))
    return ret


def read_col(H):
    '''
    H is number of rows
    A列、B列が与えられるようなとき
    ex1)A,B=read_col(H)    ex2) A,=read_col(H) 
    '''
    ret = []
    for _ in range(H):
        ret.append(list(map(int, read().split())))
    return tuple(map(list, zip(*ret)))


def read_matrix(H):
    '''
    H is number of rows
    '''
    ret = []
    for _ in range(H):
        ret.append(list(map(int, read().split())))
    return ret
    


MOD = 10**9 + 7
INF = 2**31  

from collections import defaultdict, Counter, deque
from operator import itemgetter
from itertools import product, permutations, combinations
from bisect import bisect_left, bisect_right  



N = read_a_int()
print(N // 3)

Solution (Python):
def main():
    import sys
    input = sys.stdin.readline
    N = int(input())
    print(N//3)

if __name__ == '__main__':
    main()

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

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

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

if __name__ == "__main__":
  resolve()

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):
def main():
    N = int(input())
    a, b = divmod(N, 3)
    print(a)
if __name__ == "__main__":
    main()

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

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

Solution (Python):
import math
n=int(input())
print('{:.0f}'.format(math.floor(n/3)))

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

Solution (Python):
import sys

IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))

INIT_VAL = 0
DP2 = lambda d1, d2: [[INIT_VAL]*d2 for _ in range(d1)]
DP3 = lambda d1, d2, d3: [[[INIT_VAL]*d3 for _ in range(d2)] for _ in range(d1)]

def main():
    n = II()
    print(n//3)

if __name__ == '__main__':
    main()

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

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

print(N // 3)

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

Solution (Python):
n = int(input())
if n < 3:
    print (0)
elif n == 3:
    print (1)
else:
    a = n//3
    print (a-1) if n-a <= 2 else print (a)

Solution (Python):
def resolve():
    A = int(input())
    print(A // 3)


if '__main__' == __name__:
    resolve()

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

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

Solution (Python):

import sys
input = sys.stdin.readline









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

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

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

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

Solution (Python):
url = "https://atcoder.jp/contests/abc089/tasks/abc089_a"

def main():
    n = int(input())

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

if __name__ == '__main__':
    main()

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())
res = n // 3
print(res)

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

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

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

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

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

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

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

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

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

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

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

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

print(n // 3)

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

a = n // 3
print(a)

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

print(int(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):
import math
N=int(input())
print(math.floor(N/3))

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

Solution (Python):

import math

N = int(input())
ans = math.floor(N / 3)
print(ans)

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

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

Solution (Python):
import itertools
def main():
  x = int(input())
  print(x//3)
if __name__ == '__main__':
  main()

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

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

print(int(N / 3))

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

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

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())

print(n//3)

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

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

Solution (Python):
import sys

n = int(sys.stdin.readline().rstrip())

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

if __name__ ==  '__main__':
    main()

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

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

print ( N //3 )

Solution (Python):
import sys
import copy
import math
import bisect
import pprint
import bisect
from functools import reduce
from copy import deepcopy
from collections import deque

if __name__ == '__main__':
    a = int(input())

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

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

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

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

print(N//3)

Solution (Python):
n = int(input())
ans = n//3
mod = n%3
print(max(0, ans))

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

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

Solution (Python):
import math

a=int(input())
print(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):
num = int(input())
if num < 3:
  ans = 0
else:
  ans = num//3
print(int(ans))

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


if __name__ == "__main__":
    main()

Solution (Python):
n = int(input())
if n < 3:
  print(0)
else:
  print(int(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())
cnt=0
while n>2:
  cnt+=1
  n-=3
print(cnt)

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

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

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

Solution (Python):

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

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

Solution (Python):
import math

n=int(input())

ans=math.floor(n/3)
print(ans)

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

Solution (Python):
N=int(input())
import math
print(math.floor(N/3))

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

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

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

Solution (Python):
n = int(input())
ret = n//3
if(n/3 == 0):
    ret += 1

print(ret)

Solution (Python):

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

Solution (Python):
def abc089_a(n):

    return n//3

def main():
    n = int(input())
    print(abc089_a(n))

if __name__ == '__main__':
    main()

Solution (Python):

def main():
    import sys
    
    sys.setrecursionlimit(10000000)
    from collections import Counter, deque
    
    from itertools import combinations, permutations
    
    from bisect import bisect_left,bisect_right
    from math import floor, ceil
    

    

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

if __name__ == '__main__':
    main()

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

Solution (Python):
import sys
def input(): return sys.stdin.readline().strip()
def STR(): return input()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def S_MAP(): return map(str, input().split())
def LIST(): return list(map(int, input().split()))
def S_LIST(): return list(map(str, input().split()))

def main():
    N = INT()
    print(N//3)

if __name__ == "__main__":
    main()

Solution (Python):


import sys
 
stdin = sys.stdin
inf = 1 << 60
mod = 1000000007
 
ni = lambda: int(ns())
nin = lambda y: [ni() for _ in range(y)]
na = lambda: list(map(int, stdin.readline().split()))
nan = lambda y: [na() for _ in range(y)]
nf = lambda: float(ns())
nfn = lambda y: [nf() for _ in range(y)]
nfa = lambda: list(map(float, stdin.readline().split()))
nfan = lambda y: [nfa() for _ in range(y)]
ns = lambda: stdin.readline().rstrip()
nsn = lambda y: [ns() for _ in range(y)]
ncl = lambda y: [list(ns()) for _ in range(y)]
nas = lambda: stdin.readline().split()

N = ni()

print(N // 3)

Solution (Python):
import sys
import os


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    N = int(sys.stdin.readline().rstrip())
    print(N//3)


if __name__ == '__main__':
    main()

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

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

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

print(math.floor(N/3))

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

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

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

Solution (Python):
import math
n = int(input())
ans = n / 3

ans = int(ans)

print(ans)

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):









import sys



ipti = sys.stdin.readline
MOD = 10 ** 9 + 7
INF = float('INF')
sys.setrecursionlimit(10 ** 5)

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

if __name__ == '__main__':
    main()

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

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

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

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

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

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

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

print(math.floor(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):
n = int(input())
print(n//3)

Solution (Python):

print(int(input())//3)

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

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

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

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())
rem=n%3
cnt=(n-rem)//3
print(cnt)

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

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

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

Solution (Python):


N = int(input().strip())

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):
N = input()
print N/3

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

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

print(N // 3)

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

Solution (Python):
print(eval(input() + "//3"))

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

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

print(N // 3)

Solution (Python):
import math



def readints():
    return list(map(int, input().split()))


n = int(input())
if n == 0:
    print(0)
    exit()

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

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


if __name__ == '__main__':
    main()

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

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

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

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

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

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

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

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

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

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

Solution (Python):




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


if __name__ == "__main__":
    main()

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(int(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):
import math
n=int(input())
print(math.floor(n/3))

Solution (Python):
"""
author : halo2halo
date : 24, Jan, 2020
"""

import sys
import itertools



read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

A = int(readline().decode('utf8'))

print(A//3)

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

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

Solution (Python):

print(int(input()) //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):
x = int(input())
print(int(x/3))

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

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

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

a, b = divmod(n, 3)
if n < 3:
	print(0)
else:
	print(a)

Solution (Python):
n = int(input())
count = 0

while n >= 3:
    n -= 3
    count += 1

print(count)

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

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

ans = N // 3

print(ans)

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

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