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;
		    }
		}
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz