//It is made by Awson on 2017.11.10

 #include <map>

 #include <set>

 #include <cmath>

 #include <ctime>

 #include <queue>

 #include <stack>

 #include <cstdio>

 #include <string>

 #include <vector>

 #include <cstdlib>

 #include <cstring>

 #include <iostream>

 #include <algorithm>

 #define LL long long

 #define LD long double

 #define Max(a, b) ((a) > (b) ? (a) : (b))

 #define Min(a, b) ((a) < (b) ? (a) : (b))

 #define sqr(x) ((x)*(x))

 #define y1 yy

 #define count COUNT

 #define Lr(o) (o<<1)

 #define Rr(o) (o<<1|1)

 using namespace std;

 const int N = ;

 int n;

 LL ans;

 void work() {

     scanf("%d", &n);

     for (int i = ; i <= n; i++)

     ans += n/i;

     printf("%lld\n", ans);

 }

 int main() {

     work();

     return ;

 }