import java.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long goal = sc.nextLong();
    long yen = 100;
    int ans = 0;
    while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    }
    System.out.println(ans);
  }
} import java.util.*; util.* java class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long goal = sc.nextLong();
    long yen = 100;
    int ans = 0;
    while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    }
    System.out.println(ans);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long goal = sc.nextLong();
    long yen = 100;
    int ans = 0;
    while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    }
    System.out.println(ans);
  } main {
    Scanner sc = new Scanner(System.in);
    long goal = sc.nextLong();
    long yen = 100;
    int ans = 0;
    while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    }
    System.out.println(ans);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long goal = sc.nextLong(); goal sc.nextLong() sc.nextLong sc long yen = 100; yen 100 int ans = 0; ans 0 while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    } yen < goal yen goal {
      yen = yen + (yen / 100);
      ans++;
    } yen = yen + (yen / 100) yen yen + (yen / 100) yen (yen / 100) yen 100 ans++ ans System.out.println(ans) System.out.println System.out System System.out ans String[] args args
import java.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long goal = sc.nextLong();
    long yen = 100;
    int ans = 0;
    while(yen < goal) {
      yen = yen + (yen / 100);
      ans++;
    }
    System.out.println(ans);
  }
}