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


int main(void)
{
  ll X;
  scanf("%lld",&X);
   ll dep=100;
   ll count=1;
  while (1)
  {
     dep+=(dep*1)/100;
	 if (dep<X)count++;
     else break;
  }	
  
  printf("%lld",count);
	
	return 0;
}
