#include <stdio.h>
 
int main(void)
{
  unsigned long int x;
  unsigned long int money = 100;
  int year = 0;
  
  scanf("%ld", &x);
  for(year = 0;; year++)
  {
    if(money >= x)
      break;
    money = money * 1.01;
  }
  
  printf("%d\n", year);
  return 0;
}
