#include <bits/stdc++.h>
using namespace std;
int toInt(char a) {return a - 48;}
char toStr(int a) {return char(a + 48);}
string cong(string a, string b) {
    string res;
    int remain = 0, m = max(a.length(), b.length());
    while (a.length() != m) a = '0' + a;
    while (b.length() != m) b = '0' + b;
    for (int i = m - 1; i >= 0; i--) {
        res = toStr((toInt(a[i]) + toInt(b[i]) + remain) % 10) + res;
        if (toInt(a[i]) + toInt(b[i]) + remain >= 10) remain = 1;
        else remain = 0;
    }
    if (remain > 0) res = toStr(remain) + res;
    return res;
}
string nhan1(string a, char b) {
    string res;
    int remain = 0;
    for (int i = a.length() - 1; i >= 0; i--) {
        res = toStr((toInt(a[i])*toInt(b) + remain) % 10) + res;
        if ((toInt(a[i])*toInt(b) + remain) >= 10)
            remain = (toInt(a[i])*toInt(b) + remain) / 10;
        else remain = 0;
    }
    if (remain > 0) res = toStr(remain) + res;
    return res;
}
string nhan(string a, string b) {
    string res,t,z;
    int m = min(a.length(), b.length());
    if (a.length() < b.length()) {
        t = a;
        a = b;
        b = t;
    }
    for (int i = m - 1; i >= 0; i--) {
        z = nhan1(a, b[i]);
        for (int j = (m - 1) - i; j > 0; j--) z = z + '0';
        res = cong(res, z);
    }
    return res;
}
string chia6(string a) {
    string res,n,res_not_leading_zero;
    int index;
    for (int i = 0; i < a.length(); i++) {
        n = n + a[i];
        res += to_string(stoi(n) / 6);
        n = to_string(stoi(n) - (stoi(n) / 6)*6);
    }
    for (int i = 0; i < res.length(); i++)
        if (res[i] != '0') {
            index = i;
            break;
        }
    for (int i = index; i < res.length(); i++) res_not_leading_zero += res[i];
    return res_not_leading_zero;
}
int main() {
    freopen("Cau1.inp","r",stdin);
    freopen("Cau2.inp","w",stdout);
    long long n;
    cin >> n;
    string a,b,c;
    a = to_string(n);
    b = to_string(n + 1);
    c = to_string(2*n + 1);
    cout << chia6(nhan(a,nhan(b,c)));
    return 0;
}