28237
 13190
 39914
 81367
 8554
 61106
 67448
 39004
 22308
 16054
 71468
 60501
 100
 300
 59632
 90783
 5611
 1000
 69475
 69753
 10
 5
 582
 8
 36961
 5071
 20
 53213
 92775
 28738
 100000
 92280
 37944
 9
 2627
 7
 3

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#pragma GCC optimize("O3")

#include <bits/stdc++.h>
#define int 	long long
using namespace std;

int n;
int dp[100005];
int act[100005];

signed main() {
	cin >> n;
	dp[2] = 0;
	dp[3] = 0;
	int res = 0;
	for (int i = 4; i <= n; i++) {
		long long ax = 1;
		for (int j = 2; j <= sqrt(i); j++) {
			if (i % j == 0 && ax % (i / j) != 0) {
				dp[i] += dp[i/j] + j * 4;
				ax = (ax * i/j) / __gcd(ax, i/j);
			}
		}
		for (int j = sqrt(i); j >= 2; j--) {
			if (i % j == 0 && ax % j != 0) {
				dp[i] += dp[j] + (i/j) * 4;
				ax = (ax * j) / __gcd(ax, j);
			}
		}
		for (int j = 2; j <= sqrt(i); j++) {
			if (i % j == 0) dp[j] = dp[i/j] = dp[i];
		}
		res = max(res, dp[i]);
	}
	cout << res;
}