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

int main(void)
{
  long long X;

  scanf("%lld", &X);

  long long money = 100;
  int year = 0;

  while (1)
  {
    if (money >= X)
    {
      printf("%d", year);
      return 0;
    }
    money = (long long)(money * 1.01);
    year++;
  }

  return 0;
}