#include <stdio.h>

 #define K 2

 int main(void)

 {

     int n,ans = ;

     scanf("%d",&n);

     while ()

     {

         if (n/K == && n%K == )

         {

             break;

         }

         n = n/K;

         ans ++;

     }

     printf("%d",ans);

     return ;

 }