#include <bits/stdc++.h>
using namespace std;
int arr[100]= {2,4,6,9,12,16,20,25,30,36,42,49,56,64,72,81,90,100,110,121,132,144,156,169,182,196,210,225,240,256,272,289,306,324,342,361,380,400,420,441,462,484,506,529,552,576,600,625,650,676,702,729,756,784,812,841,870,900,930,961,992,1024,1056,1089,1122,1156,1190,1225,1260,1296,1332,1369,1406,1444,1482,1521,1560,1600,1640,1681,1722,1764,1806,1849,1892,1936,1980,2025,2070,2116,2162,2209,2256,2304,2352,2401,2450,2500,2550,2601};
int main()
{
	int n;
	cin>>n;
	cout<<arr[n-1];
}