#include<stdio.h>
int n;
int f(int a)
{
	int x=1;
	while(a>=10)
	{
		x++;
		a/=10;
	}
	return x;
}
int main()
{
	int ans=0,n;
	scanf("%d",&n);
	ans=f(n);
	while(n!=1)
	{
		ans+=f(n/2);
		n/=2;
	}
	printf("%d",ans);
	return 0;
} 
/**************************************************************
	Problem: 1562
	User: admin
	Language: C
	Result: Accepted
	Time:44 ms
	Memory:1144 kb
****************************************************************/