#include<bits/stdc++.h>
using namespace std;
int main()
{
	int s,ans=0;
	double y=2;
	cin>>s;
	for(int i=1;i<=10000;i++)
	{
		y*=0.98;
		if(y>s)
		{
			break;	
		}else{
			if(y==s)
			{
				ans++;
				break;	
			}else{
				y=y+y;
				ans++;	
			}
		}
	}
	cout<<ans+1;
	return 0;
}