#include<stdio.h>
#include<math.h>

int main(void) {
  unsigned long int x;
  unsigned long int n=100;
  unsigned long int prev_n;
  unsigned long int count=0;
  unsigned long int prev_count;
  unsigned long int money_zouka;
  unsigned long int year_zouka;
  scanf("%ld", &x);
  while(n < x) {
    prev_n = n;
    prev_count = count;
    money_zouka = n / 100;
    year_zouka = (unsigned long int)ceil((double)(100-n%100)/money_zouka);
    count += year_zouka;
    n += money_zouka * year_zouka;
  }
  //printf("%ld, %ld\n", prev_n, prev_count);
  while(prev_n < x) {
    prev_n += prev_n / 100;
    prev_count++;
  }
  printf("%ld\n", prev_count);
  return 0;
}
