import java.io.InputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	InputStream in = System.in;
	PrintStream out = System.out;

	public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	}

	public static void main(String[] args) {
		new Main()._main(args);
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}
} import java.io.InputStream; InputStream java.io import java.io.PrintStream; PrintStream java.io import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	InputStream in = System.in;
	PrintStream out = System.out;

	public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	}

	public static void main(String[] args) {
		new Main()._main(args);
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}
} Main InputStream in = System.in; in System.in System System.in PrintStream out = System.out; out System.out System System.out public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	} _main {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	} Scanner sc = new Scanner(in); sc new Scanner(in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc sc.close() sc.close sc long ans = 100; ans 100 int y = 1; y 1 for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		} ; y++ y++ y {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		} {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		} ans *= 1.01 ans 1.01 if(ans >= X) {
				break;
			} ans >= X ans X {
				break;
			} break; out.println(y) out.println out y String[] args args public static void main(String[] args) {
		new Main()._main(args);
	} main {
		new Main()._main(args);
	} new Main()._main(args) new Main()._main new Main() args String[] args args @SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	} join {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	} StringBuilder sb = new StringBuilder(); sb new StringBuilder() for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		} int i = 0; int i = 0; i 0 i < a.length i a.length a a.length i++ i++ i {
			sb.append(a[i]);
			sb.append(delimiter);
		} {
			sb.append(a[i]);
			sb.append(delimiter);
		} sb.append(a[i]) sb.append sb a[i] a i sb.append(delimiter) sb.append sb delimiter return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0)); sb.substring(0, Math.max(sb.length() - delimiter.length(), 0)) sb.substring sb 0 Math.max(sb.length() - delimiter.length(), 0) Math.max Math sb.length() - delimiter.length() sb.length() sb.length sb delimiter.length() delimiter.length delimiter 0 String delimiter delimiter int[] a a @SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	} join {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	} StringBuilder sb = new StringBuilder(); sb new StringBuilder() for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		} int i = 0; int i = 0; i 0 i < a.length i a.length a a.length i++ i++ i {
			sb.append(a[i]);
			sb.append(delimiter);
		} {
			sb.append(a[i]);
			sb.append(delimiter);
		} sb.append(a[i]) sb.append sb a[i] a i sb.append(delimiter) sb.append sb delimiter return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0)); sb.substring(0, Math.max(sb.length() - delimiter.length(), 0)) sb.substring sb 0 Math.max(sb.length() - delimiter.length(), 0) Math.max Math sb.length() - delimiter.length() sb.length() sb.length sb delimiter.length() delimiter.length delimiter 0 String delimiter delimiter long[] a a @SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	} max {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	} if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} arr == null || arr.length == 0 arr == null arr null arr.length == 0 arr.length arr arr.length 0 {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} throw new IllegalArgumentException(Arrays.toString(arr)); new IllegalArgumentException(Arrays.toString(arr)) int candidate = arr[0]; candidate arr[0] arr 0 for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} int i=1; int i=1; i 1 i<arr.length i arr.length arr arr.length i++ i++ i {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} candidate = candidate > arr[i] ? candidate : arr[i] candidate candidate > arr[i] ? candidate : arr[i] candidate > arr[i] candidate arr[i] arr i candidate arr[i] arr i return candidate; candidate int[] arr arr @SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	} max {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	} if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} arr == null || arr.length == 0 arr == null arr null arr.length == 0 arr.length arr arr.length 0 {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} throw new IllegalArgumentException(Arrays.toString(arr)); new IllegalArgumentException(Arrays.toString(arr)) long candidate = arr[0]; candidate arr[0] arr 0 for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} int i=1; int i=1; i 1 i<arr.length i arr.length arr arr.length i++ i++ i {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} {
			candidate = candidate > arr[i] ? candidate : arr[i];
		} candidate = candidate > arr[i] ? candidate : arr[i] candidate candidate > arr[i] ? candidate : arr[i] candidate > arr[i] candidate arr[i] arr i candidate arr[i] arr i return candidate; candidate long[] arr arr @SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	} min {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	} if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} arr == null || arr.length == 0 arr == null arr null arr.length == 0 arr.length arr arr.length 0 {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} throw new IllegalArgumentException(Arrays.toString(arr)); new IllegalArgumentException(Arrays.toString(arr)) int candidate = arr[0]; candidate arr[0] arr 0 for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} int i=1; int i=1; i 1 i<arr.length i arr.length arr arr.length i++ i++ i {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} candidate = candidate < arr[i] ? candidate : arr[i] candidate candidate < arr[i] ? candidate : arr[i] candidate < arr[i] candidate arr[i] arr i candidate arr[i] arr i return candidate; candidate int[] arr arr @SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	} min {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	} if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} arr == null || arr.length == 0 arr == null arr null arr.length == 0 arr.length arr arr.length 0 {
			throw new IllegalArgumentException(Arrays.toString(arr));
		} throw new IllegalArgumentException(Arrays.toString(arr)); new IllegalArgumentException(Arrays.toString(arr)) long candidate = arr[0]; candidate arr[0] arr 0 for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} int i=1; int i=1; i 1 i<arr.length i arr.length arr arr.length i++ i++ i {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} {
			candidate = candidate < arr[i] ? candidate : arr[i];
		} candidate = candidate < arr[i] ? candidate : arr[i] candidate candidate < arr[i] ? candidate : arr[i] candidate < arr[i] candidate arr[i] arr i candidate arr[i] arr i return candidate; candidate long[] arr arr @SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	} nextIntArray {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	} int[] result = new int[n]; result new int[n] n for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			result[i] = sc.nextInt();
		} {
			result[i] = sc.nextInt();
		} result[i] = sc.nextInt() result[i] result i sc.nextInt() sc.nextInt sc return result; result Scanner sc sc int n n @SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	} nextLongArray {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	} long[] result = new long[n]; result new long[n] n for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			result[i] = sc.nextLong();
		} {
			result[i] = sc.nextLong();
		} result[i] = sc.nextLong() result[i] result i sc.nextLong() sc.nextLong sc return result; result Scanner sc sc int n n @SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	} nextIntArray1origin {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	} int[] result = new int[n + 1]; result new int[n + 1] n + 1 n 1 for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		} int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
			result[i] = sc.nextInt();
		} {
			result[i] = sc.nextInt();
		} result[i] = sc.nextInt() result[i] result i sc.nextInt() sc.nextInt sc return result; result Scanner sc sc int n n public class Main {
	InputStream in = System.in;
	PrintStream out = System.out;

	public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	}

	public static void main(String[] args) {
		new Main()._main(args);
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}
} public class Main {
	InputStream in = System.in;
	PrintStream out = System.out;

	public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	}

	public static void main(String[] args) {
		new Main()._main(args);
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}
} Main
import java.io.InputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	InputStream in = System.in;
	PrintStream out = System.out;

	public void _main(String[] args) {
		Scanner sc = new Scanner(in);

		long X = sc.nextLong();
		
		sc.close();

		long ans = 100;
		int y = 1;
		for(;;y++) {
			ans *= 1.01;
			
			if(ans >= X) {
				break;
			}
		}
		out.println(y);
		
	}

	public static void main(String[] args) {
		new Main()._main(args);
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, int[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private String join(String delimiter, long[] a) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < a.length; i++) {
			sb.append(a[i]);
			sb.append(delimiter);
		}
		return sb.substring(0, Math.max(sb.length() - delimiter.length(), 0));
	}

	@SuppressWarnings("unused")
	private int max(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long max(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate > arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int min(int[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		int candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private long min(long[] arr) {
		if(arr == null || arr.length == 0) {
			throw new IllegalArgumentException(Arrays.toString(arr));
		}

		long candidate = arr[0];
		for(int i=1;i<arr.length;i++) {
			candidate = candidate < arr[i] ? candidate : arr[i];
		}
		return candidate;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray(Scanner sc, int n) {
		int[] result = new int[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private long[] nextLongArray(Scanner sc, int n) {
		long[] result = new long[n];
		for (int i = 0; i < n; i++) {
			result[i] = sc.nextLong();
		}
		return result;
	}

	@SuppressWarnings("unused")
	private int[] nextIntArray1origin(Scanner sc, int n) {
		int[] result = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			result[i] = sc.nextInt();
		}
		return result;
	}
}
