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

int main(){
  long long int x;
  scanf("%lld",&x);
  
  int cnt=0;
  
  //yen+=yen*0.01;
  
  for(long long int yen=100;yen<x;yen+=yen*0.01) cnt++;
  
  printf("%lld",cnt);
  return 0;
}