#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define ll long long

int main(){
  ll x, now= 100, cnt = 0;
  scanf("%lld", &x);
  do
  {
    now += now/100;
    cnt++;
    /* code */
  } while (x > now);
  
  printf("%lld\n", cnt);
  return 0;
}