/*
TASK:minitime
LANG:C++
*/
#include<iostream>
using namespace std;
int main(){
    int br=1,ind=4,n,n1,a[107]={0},k=0;
    cin>>n;
    a[0]=1;
    a[1]=2;
    a[2]=3;
    while (ind<107)
    {
       for(int i=0;i<br;i++)
        {a[ind+i-1]=br+2; /*cout<<a[i]<<endl;*/ k=i;}
       ind=ind+k; 
       br++;     
            
     }
    cout<<a[n-1]; 
    system("pause");
    return 0;
}
