#include <stdio.h>
int main(void){
  long long int  x;
  double a=100;  //now
  int y=0;
  int b=100;   //now

  scanf("%lld",&x);

  while(b<x){
    a+=a/100;
    b=a;
    y++;
  }


  printf("%d",y);

  return 0;
  }