#include <stdio.h>
#include <limits.h>
int main(void)
{
  signed long long int a;
  signed long long int total=100;
  int count=0;
  scanf("%lld",&a);
  while(total <= a)
  {
     total = total * 1.01;
     count++;
     /**
     printf("%ld\n",total);
     **/
     if(total >= a)
     {
       printf("%d",count);
       break;
     }
  }
 
  return 0;
}