#include <iostream>
#include <math.h>
using namespace std;
double Log2( double n )  
{  
    // log(n)/log(2) is log2.  
	return log( n ) / log( 2.0 );  
} 
int main(int argc, char* argv[])
{
	int N;
	cin>>N;
	double n=Log2((double)N);
	if (n!=(int)n){
		n++;
	}
	cout<<(int)n<<endl;
	return 0;
}