	public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		}
	 
	} public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		}
	 
	} Main public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		} main {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		} java.util.Scanner scan = new java.util.Scanner(System.in); scan new java.util.Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan long m = 100; m 100 for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			} int i = 1 ; int i = 1 ; i 1 m < x m x i++ i++ i {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			} {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			} m = m / 100 + m m m / 100 + m m / 100 m 100 m if (m >= x) {
					System.out.println(i);
				} m >= x m x {
					System.out.println(i);
				} System.out.println(i) System.out.println System.out System System.out i String[] args args public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		}
	 
	} public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		}
	 
	} Main
	public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					System.out.println(i);
				}
			}
	 
		}
	 
	}
