/*
TASK:MINITIME
LANG:C++
*/
#include<iostream.h>
using namespace std;
int main()
{
    int n,k,p,ts,ms;
    cin>>n;
    ms=n;
    for(k=2;k<=n;k++)
    {
                     if(n%k==0)p=n/k;
                     else p=n/k+1;
                     ts=k+p;
                     if(ts<ms)ms=ts;
    }
    cout<<ms<<endl;
    system("pause");
}
                     
                    
