/*
TASK:minitime
LANG:C++
*/
#include<iostream>
using namespace std;
int main()
{
    unsigned long long int n;
    cin>>n;
    if(n<4&&n>0) cout<<n;
    else
    {
        if(n%2==0) cout<<2+n/2;
        else cout<<3+n/2;
    }
    //system("PAUSE");
    return 0;
}
