#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int main()
{
long long x;
cin>>x;
long long l=x,r=x*2,mid;
while (l<r)
{
mid=(l+r)/2;
if (log(mid*1.0)*mid-mid+0.5*log(mid)+0.999999<x*log(x))
{
l=mid+1;
}
else
{
r=mid;
}
}
cout<<l;
return 0;
}
题解在这