source_code: 
  import java.io.*;
  import java.util.*;
  
  public class C {
  
  	public static void main(String[] args) throws IOException {
  		FastScanner in = new FastScanner(System.in);
  		PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
  
  		int n = in.nextInt();
  		double r = in.nextInt();
  		double[] x = new double[n+1];
  		double[] y = new double[n+1];
  		for (int i = 1; i <= n; i++) {
  			x[i] = in.nextInt();
  		}
  		
  		int[] lastx = new int[1001];
  		for (int i = 1; i <= n; i++) {
  			double s = x[i] - r, e = x[i] + r;
  			for (int j = (int)Math.max(0, s); j <= (int)Math.min(1000, e); j++) {
  				if (lastx[j] == 0) {
  					y[i] = Math.max(y[i], findY(x[i], x[i], 0 - r, 2 * r));
  				}
  				else {
  					y[i] = Math.max(y[i], findY(x[lastx[j]], x[i], y[lastx[j]], 2 * r));
  				}
  				lastx[j] = i;
  			}
  		}
  		
  		for (int i = 1; i <= n; i++) {
  			out.println(y[i]);
  		}
  		out.close();
  	}
  	
  	public static double findY(double x1, double x2, double y1, double d) {
  		return Math.max(y1 + Math.sqrt(-1 * Math.pow(x1, 2) + 2 * x1 * x2 + Math.pow(d, 2) - Math.pow(x2, 2)),
  				y1 - Math.sqrt(-1 * Math.pow(x1, 2) + 2 * x1 * x2 + Math.pow(d, 2) - Math.pow(x2, 2)));
  	}
  
  	static class FastScanner {
  		private InputStream stream;
  		private byte[] buf = new byte[1024];
  		private int curChar;
  		private int numChars;
  
  		public FastScanner(InputStream stream) {
  			this.stream = stream;
  		}
  
  		int read() {
  			if (numChars == -1)
  				throw new InputMismatchException();
  			if (curChar >= numChars) {
  				curChar = 0;
  				try {
  					numChars = stream.read(buf);
  				} catch (IOException e) {
  					throw new InputMismatchException();
  				}
  				if (numChars <= 0)
  					return -1;
  			}
  			return buf[curChar++];
  		}
  
  		boolean isSpaceChar(int c) {
  			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  		}
  
  		boolean isEndline(int c) {
  			return c == '\n' || c == '\r' || c == -1;
  		}
  
  		public int nextInt() {
  			return Integer.parseInt(next());
  		}
  
  		public long nextLong() {
  			return Long.parseLong(next());
  		}
  
  		public double nextDouble() {
  			return Double.parseDouble(next());
  		}
  
  		public String next() {
  			int c = read();
  			while (isSpaceChar(c))
  				c = read();
  			StringBuilder res = new StringBuilder();
  			do {
  				res.appendCodePoint(c);
  				c = read();
  			} while (!isSpaceChar(c));
  			return res.toString();
  		}
  
  		public String nextLine() {
  			int c = read();
  			while (isEndline(c))
  				c = read();
  			StringBuilder res = new StringBuilder();
  			do {
  				res.appendCodePoint(c);
  				c = read();
  			} while (!isEndline(c));
  			return res.toString();
  		}
  	}
  
  }
  