import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	}

	static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		}
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.InputStreamReader; InputStreamReader java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	}

	static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		}
} Main public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	} main {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	} FastScanner sc = new FastScanner(System.in); sc new FastScanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long money = 100; money 100 int count = 0; count 0 while(money < x) {
			money += money/100;
			count++;
		} money < x money x {
			money += money/100;
			count++;
		} money += money/100 money money/100 money 100 count++ count System.out.println(count) System.out.println System.out System System.out count String[] args args static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		} FastScanner private BufferedReader reader = null; reader null private StringTokenizer tokenizer = null; tokenizer null public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    } FastScanner {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    } reader = new BufferedReader(new InputStreamReader(in)) reader new BufferedReader(new InputStreamReader(in)) tokenizer = null tokenizer null InputStream in in public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    } next {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        } try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            } IOException e {
		                throw new RuntimeException(e);
		            } throw new RuntimeException(e); new RuntimeException(e) {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    } nextLine {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        } try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            } IOException e {
		                throw new RuntimeException(e);
		            } throw new RuntimeException(e); new RuntimeException(e) {
		                return reader.readLine();
		            } return reader.readLine(); reader.readLine() reader.readLine reader return tokenizer.nextToken("\n"); tokenizer.nextToken("\n") tokenizer.nextToken tokenizer "\n" public long nextLong() {
		        return Long.parseLong(next());
		    } nextLong {
		        return Long.parseLong(next());
		    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public int nextInt() {
		        return Integer.parseInt(next());
		    } nextInt {
		        return Integer.parseInt(next());
		    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public double nextDouble() {
		         return Double.parseDouble(next());
		     } nextDouble {
		         return Double.parseDouble(next());
		     } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    } nextIntArray {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    } int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++)
		            a[i] = nextInt(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextInt(); a[i] = nextInt() a[i] a i nextInt() nextInt return a; a int n n public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    } nextLongArray {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    } long[] a = new long[n]; a new long[n] n for (int i = 0; i < n; i++)
		            a[i] = nextLong(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextLong(); a[i] = nextLong() a[i] a i nextLong() nextLong return a; a int n n public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	}

	static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		}
} public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	}

	static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		}
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) {
		FastScanner sc = new FastScanner(System.in);
		long x = sc.nextLong();
		long money = 100;
		int count = 0;

		while(money < x) {
			money += money/100;
			count++;
		}

		System.out.println(count);
	}

	static class FastScanner {
			private BufferedReader reader = null;
		    private StringTokenizer tokenizer = null;
		    public FastScanner(InputStream in) {
		        reader = new BufferedReader(new InputStreamReader(in));
		        tokenizer = null;
		    }

		    public String next() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                tokenizer = new StringTokenizer(reader.readLine());
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }
		        return tokenizer.nextToken();
		    }

		    public String nextLine() {
		        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
		            try {
		                return reader.readLine();
		            } catch (IOException e) {
		                throw new RuntimeException(e);
		            }
		        }

		        return tokenizer.nextToken("\n");
		    }

		    public long nextLong() {
		        return Long.parseLong(next());
		    }

		    public int nextInt() {
		        return Integer.parseInt(next());
		    }

		    public double nextDouble() {
		         return Double.parseDouble(next());
		     }

		    public int[] nextIntArray(int n) {
		        int[] a = new int[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextInt();
		        return a;
		    }

		    public long[] nextLongArray(int n) {
		        long[] a = new long[n];
		        for (int i = 0; i < n; i++)
		            a[i] = nextLong();
		        return a;
		    }
		}
}
