#include <iostream>
using namespace std;
typedef long long LL;
int main(int argc, char* argv[])
{
	LL N;
	cin>>N;
	if (N==1){
		cout<<0<<endl;
		return 0;
	}
	int aw=0;
	while(N>1){
		if (N%2==1){
			N++;
			aw++;
		}
		N/=2;
		aw++;
	}
	cout<<aw<<endl;
	return 0;
}