import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
//	入力の読み込み
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();  //目標金額
		long total = 100L;  //預金金額
		int count = 0;  //何年後か
//	totalがxを超えるまで繰り返す
		while(total < x) {
			total *= 1.01;
			count++;  //何年たったかカウントする
		}
		System.out.print(count);
	}
}

/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