#include <stdio.h>
#include <stdint.h>

int64_t totalYokin(int64_t yokin){
  return yokin * 1.01;
}

int main()
{
  int64_t yokin = 100;
  int64_t x;
  int year = 0;

  scanf("%ld",&x);

  while (yokin < x) {
    yokin = totalYokin(yokin);
    year++;
  }
  printf("%d\n", year);
  return 0;
}

