import collections
import heapq
import sys
import math
import itertools
import bisect
from io import BytesIO, IOBase
import os
def valid(i,j,n,m):
if i<n and i>=0 and j>=0 and j< m :return True return False
def sumn(i,n):
return (n-i)*(i+n)/2
def sqfun(a,b,c):
return (-b+math.sqrt(b*b-4*a*c))/2*a
def getprime(num):
if all(num%i!=0 for i in range(2,int(math.sqrt(num))+1)):return True
def value(): return tuple(map(int, input().split()))
def values(): return tuple(map(int, sys.stdin.readline().split()))
def inlst(): return [int(i) for i in input().split()]
def inlsts(): return [int(i) for i in sys.stdin.readline().split()]
def inp(): return int(input())
def inps(): return int(sys.stdin.readline())
def instr(): return input()
def stlst(): return [i for i in input().split()]
def solve():
n = inp()
if n==1:return 3
return 4+(4*n-3)//3
if __name__ == "__main__":
print(solve())
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define M 1
//tc fori forj
//1 sec -10^8
//max len of arr -10^7
//max len of vector 2147483648 < 10^10
//for loops not more that 10^5
//QUALITY>QUANTITY
// NO WRONG SUBMISSIONS ONLY CORRECT ANSWERS
//-------------------------------------------------------------------------------------------------------------------------------
//
//FIRST YOU SHOULD GET THE LOGIC CORRECTLY , READ THE QUESTION CORRECTLY
//
//-------------------------------------------------------------------------------------------------------------------------------
//===============================================vignesh========================================================================
void solve()
{
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll n;
cin>>n;
if (n==1)
{
cout<<3;
}
else if (n==2)
{
cout<<5;
}
else if (n==3)
{
cout<<7;
}
else
{
ll mo=n%3;
n=(n-1)/3;
n=(n+1)*4;
if (mo==1)
{
n+=0;
}
if (mo==2)
{
n+=1;
}
else if (mo==0)
{
n+=3;
}
cout<<n;
}
}150. Evaluate Reverse Polish Notation | 144. Binary Tree Preorder Traversal |
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