import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
      	long now = 100;
      	double p = 0;
      	int i =0;

	while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    }
            System.out.println(i);
    }
} import java.util.*; util.* java class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
      	long now = 100;
      	double p = 0;
      	int i =0;

	while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    }
            System.out.println(i);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
      	long now = 100;
      	double p = 0;
      	int i =0;

	while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    }
            System.out.println(i);
    } main {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
      	long now = 100;
      	double p = 0;
      	int i =0;

	while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    }
            System.out.println(i);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long now = 100; now 100 double p = 0; p 0 int i =0; i 0 while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    } x > now x now {
      p = now * 0.01;
      now = now + (long)p;
      i++;
    } p = now * 0.01 p now * 0.01 now 0.01 now = now + (long)p now now + (long)p now (long)p i++ i System.out.println(i) System.out.println System.out System System.out i String[] args args
import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
      	long now = 100;
      	double p = 0;
      	int i =0;

	while (x > now){
      p = now * 0.01;
      now = now + (long)p;
      i++;
    }
            System.out.println(i);
    }
}