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

typedef unsigned long long int ull;
typedef long long int ll;
typedef long double ld;

int main(void) {
  int scan; // scanf result
  ull n; // to input 
  ull amount;
  ull count;

  scan = scanf("%llu", &n);
  amount = 100;
  count = 0;
  while (amount < n)
  {
    amount *= (1 + 0.01);
    count++;
  }
   
  printf("%llu", count); 
  return (0);
}
