/*
TASK:minitime
LANG:C++
*/
#include<iostream>
using namespace std;
int main ()
{
    int n,i,j,k,l,p,t;
    cin>>n;
    j=n;
    for(i=1;i<=n;i++){
        k=i;
        t=n/i;
        p=n/i+1;
        if(k+p<j){j=k+p;
}    }
    cout<<j<<"\n";
return 0;
    }
    
