#include <bits/stdc++.h>
// #include <atcoder/all>
using namespace std;
// using namespace atcoder;
#define rep(i, n) for(int i =0; i < (n); i++)
using ll = long long int;

int main() {
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	//freopen("input.txt", "r", stdin);
	int n; cin >> n;
	vector<int> dp(n+1, 1e9);
	dp[1] = 0;

	for (int i = 1; i <= n; i++) {
		if (dp[i] == 1e9) continue;

		for (int k = 2; i*k <= n; k++) {
			dp[i*k] = min(dp[i*k], dp[i] + k);
		}
	}
	cout << dp[n] << endl;

	
	return 0;  
}