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

int main(void) {
  long long int x;
  scanf("%lld", &x);
  long long int cash = 100;
  long long int count = 0;
  while (cash < x) {
    cash += cash * 0.01;
    count++;
  }
  printf("%lld\n", count);

  return 0;
}
