#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#define ll long long int

int main(){
  ll x;
  scanf("%lld",&x);

  ll m=100;
  ll count=0;
  while(x>m){
    m+=m/100;
    count++;}
  printf("%lld\n",count);
  
  return 0;
}
