#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
int main(){
 long long x,money=100;
 long long year=0;
 scanf("%lld",&x);
 while(money<x){
  year++;
  money+=money*0.01;
 }
  
 printf("%lld\n",year);
return 0;} 