package main;

import java.math.BigInteger;

public class Main6 {
	public static void main(String[] args) {
		int n=2;
		double sqrt=Math.sqrt(n);
		String sqrtStr=sqrt+0.0001+"";
		int pointIndex=sqrtStr.indexOf(".");
		String left=null;
		if(pointIndex==-1){
			System.out.println("结果为"+sqrtStr);
		}else{
			left=sqrtStr.substring(0,pointIndex+2);//
		}
		int leftNum=Integer.parseInt(sqrtStr.substring(0,pointIndex));
		int rightNum=Integer.parseInt(sqrtStr.substring(pointIndex+1,pointIndex+2));
		String aStr=((n-leftNum*leftNum)*100-(leftNum*20+rightNum)*rightNum)*100+"";
		String bStr=left.replace(".","");
		BigInteger a=new BigInteger(aStr);
		BigInteger b=new BigInteger(bStr);
		BigInteger num20=new BigInteger("20");
		BigInteger num100=new BigInteger("100");
		BigInteger num10=new BigInteger("10");
		BigInteger num0=new BigInteger("0");
		StringBuilder sb = new StringBuilder(left);//2704
		for (int i = 0; i < 700; i++) {
			int c = 0;
			try {
				c = chufa(a,b);
			} catch (Exception e) {
				e.printStackTrace();
				throw new RuntimeException("--bbb--");
			}
			sb.append(c);
			BigInteger bigC=new BigInteger(c+"");
			//int d=(b*20+c)*c;
			BigInteger d=b.multiply(num20).add(bigC).multiply(bigC);
			if(a.subtract(d).compareTo(num0)<0){
				throw new RuntimeException("--ERROR--"+i);
			}
			a=a.subtract(d).multiply(num100);
			b=b.multiply(num10).add(bigC);
		}
		System.out.println(sb.toString());
	}
	public static void main2(String[] args) {
		int a=400;
		int b=14;
		for (int i = 0; i < 10; i++) {
			int c=a/10/2/b;
			int d=(b*20+c)*c;
			a=(a-d)*100;
			b=b*10+c;
		}

	}
	public static void main3(String[] args) {
		long a=400;
		long b=14;
		for (int i = 0; i < 10; i++) {
			int c=(int)(a/10/2/b);
			long d=(b*20+c)*c;
			a=(a-d)*100;
			b=b*10+c;
		}

	}
	public static int ji(int shiWei,int geWei){
		return (shiWei*20+geWei)*geWei;
	}
	public static int chufa(BigInteger a,BigInteger b){
		if(a.toString().length()<9){
			return a.intValue()/20/b.intValue();
		}else{
			String aa=a.toString();
			String bb=b.toString();
			String aaa=aa.substring(0,8);
			String bbb=bb.substring(0,bb.length()-(aa.length()-8));
			try {
				if(Integer.parseInt(aaa)/Integer.parseInt(bbb)/20>10){
					throw new RuntimeException("--过大--"+Integer.parseInt(aaa)/Integer.parseInt(bbb)/20);
				}
				return Integer.parseInt(aaa)/20/Integer.parseInt(bbb);
			} catch (NumberFormatException e) {
				throw new RuntimeException("--aaaa--");
			}
		}
	}
}