/* | |
* Written by Nitin Kumar Maharana | |
* [email protected] | |
*/ | |
using namespace std; | |
int main(void) | |
{ | |
int n; | |
long result; | |
cin >> n; | |
result = 0l; | |
result += n; | |
for(int i = 2; i <= n/2; i++) | |
{ | |
if(i*i <= n) | |
result += (i-1); | |
else | |
{ | |
for(int j = 2; i*j <= n; j++) | |
result++; | |
} | |
} | |
cout << result << endl; | |
return 0; | |
} |