#include <iostream>
#include <cmath>
int main()
{
int n;
std::cin>>n;
std::cout<<ceil(log(n)/log(2));
return 0;
}
#include <iostream>
#include <cmath>
int main()
{
int n;
std::cin>>n;
std::cout<<ceil(log(n)/log(2));
return 0;
}