Problem: Hyakugoku has just retired from being the resident deity of the South Black Snail Temple in order to pursue her dream of becoming a cartoonist. She spent six months in that temple just playing "Cat's Cradle" so now she wants to try a different game — "Snakes and Ladders". Unfortunately, she already killed all the snakes, so there are only ladders left now. 

The game is played on a 10 × 10 board as follows:

  * At the beginning of the game, the player is at the bottom left square. 
  * The objective of the game is for the player to reach the Goal (the top left square) by following the path and climbing vertical ladders. Once the player reaches the Goal, the game ends. 
  * The path is as follows: if a square is not the end of its row, it leads to the square next to it along the direction of its row; if a square is the end of its row, it leads to the square above it. The direction of a row is determined as follows: the direction of the bottom row is to the right; the direction of any other row is opposite the direction of the row below it. See Notes section for visualization of path. 
  * During each turn, the player rolls a standard six-sided dice. Suppose that the number shown on the dice is r. If the Goal is less than r squares away on the path, the player doesn't move (but the turn is performed). Otherwise, the player advances exactly r squares along the path and then stops. If the player stops on a square with the bottom of a ladder, the player chooses whether or not to climb up that ladder. If she chooses not to climb, then she stays in that square for the beginning of the next turn. 
  * Some squares have a ladder in them. Ladders are only placed vertically — each one leads to the same square of some of the upper rows. In order for the player to climb up a ladder, after rolling the dice, she must stop at the square containing the bottom of the ladder. After using the ladder, the player will end up in the square containing the top of the ladder. She cannot leave the ladder in the middle of climbing. And if the square containing the top of the ladder also contains the bottom of another ladder, she is not allowed to use that second ladder. 
  * The numbers on the faces of the dice are 1, 2, 3, 4, 5, and 6, with each number having the same probability of being shown. 



Please note that: 

  * it is possible for ladders to overlap, but the player cannot switch to the other ladder while in the middle of climbing the first one; 
  * it is possible for ladders to go straight to the top row, but not any higher; 
  * it is possible for two ladders to lead to the same tile; 
  * it is possible for a ladder to lead to a tile that also has a ladder, but the player will not be able to use that second ladder if she uses the first one; 
  * the player can only climb up ladders, not climb down. 



Hyakugoku wants to finish the game as soon as possible. Thus, on each turn she chooses whether to climb the ladder or not optimally. Help her to determine the minimum expected number of turns the game will take.

Input

Input will consist of ten lines. The i-th line will contain 10 non-negative integers h_{i1}, h_{i2}, ..., h_{i10}. If h_{ij} is 0, then the tile at the i-th row and j-th column has no ladder. Otherwise, the ladder at that tile will have a height of h_{ij}, i.e. climbing it will lead to the tile h_{ij} rows directly above. It is guaranteed that 0 ≤ h_{ij} < i. Also, the first number of the first line and the first number of the last line always contain 0, i.e. the Goal and the starting tile never have ladders.

Output

Print only one line containing a single floating-point number — the minimum expected number of turns Hyakugoku can take to finish the game. Your answer will be considered correct if its absolute or relative error does not exceed 10^{-6}.

Examples

Input


0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0


Output


33.0476190476


Input


0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 3 0 0 0 4 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 4 0 0 0
0 0 3 0 0 0 0 0 0 0
0 0 4 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 9


Output


20.2591405923


Input


0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 6 6 6 6 6 6 0 0 0
1 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0


Output


15.9047592939

Note

A visualization of the path and the board from example 2 is as follows: <image>

The tile with an 'S' is the starting tile and the tile with an 'E' is the Goal.

For the first example, there are no ladders.

For the second example, the board looks like the one in the right part of the image (the ladders have been colored for clarity).

It is possible for ladders to overlap, as is the case with the red and yellow ladders and green and blue ladders. It is also possible for ladders to go straight to the top, as is the case with the black and blue ladders. However, it is not possible for ladders to go any higher (outside of the board). It is also possible that two ladders lead to the same tile, as is the case with the red and yellow ladders. Also, notice that the red and yellow ladders lead to the tile with the orange ladder. So if the player chooses to climb either of the red and yellow ladders, they will not be able to climb the orange ladder. Finally, notice that the green ladder passes through the starting tile of the blue ladder. The player cannot transfer from the green ladder to the blue ladder while in the middle of climbing the green ladder.

Solution (in JAVA):

Solution:
// Hash: 1+un7ZLATBnxwAC3sitW7wAobdpeQjjo7a+iGdSr/r8=

import java.security.*;
import java.lang.annotation.*;
import java.nio.file.StandardOpenOption;
import java.util.stream.*;
import java.nio.file.Files;
import java.util.function.*;
import java.util.concurrent.*;
import java.util.*;
import java.nio.file.Paths;
import java.util.concurrent.atomic.AtomicReference;
import java.text.SimpleDateFormat;
import java.nio.charset.*;
import java.nio.file.Path;
import java.io.*;
import java.lang.reflect.*;
import java.text.DecimalFormat;
import java.math.*;



// Solution can be found in Submission.testCase(). psvm method can be found in Main.main(String[] args)
// Please note that the code isn't obfuscated; only compressed


public class Solution {
    public static void main(String[] args) throws Exception {
        Main.main(args);
    }
}


class Main{public static void main(String[]args)throws Exception{Class<?extends AbstractSubmission>clss=TaskE.class;new TaskE().runSubmission();}};







@ContestSubmission(ContestType.CODEFORCES)
@CacheVersion(0)
class TaskE extends AbstractSubmission {

	@Override
	public void testCase() {
		int[][] grid = new int[10][10];
		for (int i = 0; i < 10; i++) {
			for (int j = 0; j < 10; j++) {
				grid[i][j] = sc.nextInt();
			}
		}

		int[] tablo = new int[100];
		{
			int x = 0;
			int y = 0;
			int rev = 1;
			for (int i = 0; i < tablo.length; i++) {
				tablo[i] = grid[y][x];
				x += rev;
				if (x < 0 || x >= 10) {
					rev *= -1;
					x += rev;
					y++;
				}
			}
		}

		int[] lds = new int[100];
		for (int i = 0; i < 100; i++) {
			lds[i] = 100 - ldist(100 - i, tablo[i]);
		}
		debug.println(ldist(9, 8));
		
		double[] DP = new double[100];
		DP[0] = 0;
		for (int i = 1; i < DP.length; i++) {
			int tot = 0;
			for (int d = 1; d <= 6; d++) {
				if (d > i) continue;
				DP[i] += Math.min(DP[i - d], DP[lds[i-d]]);
				tot++;
			}
			DP[i] /= tot;
			DP[i] += 6.0 / tot;
		}

		out.println(DP[99]);
	}

	public static int ldist(int pos, int height) {
		if (height % 2 == 0) return height * 10 + pos;
		return ldist(pos + (int) (2 * (10.5 - (pos - 1) % 10 - 1)), height - 1);
	}



	@Override
	public void init() {
		// Nothing here! Good for initializing look-up tables or cached values

		// Note that there could be multiple Problem instances running on different threads. Writing static variables
		// here (or anywhere else) could lead to race conditions! Use static initialization instead
	}











	// Set to TRUE to override default (which may both be true or false). Setting to FALSE has no effect

	/* DISABLE-CODE-COMPRESSION: TRUE */
	/* GLOBAL-DISABLE-CODE-COMPRESSION: DEFAULT */
	/* JAVA-6-COMPATIBILITY-MODE: DEFAULT */
	/* KEEP-UNUSED-DEPENDENCIES: DEFAULT */





	
};

abstract class AbstractSubmission{public FastScanner sc;public InputStream in;public PrintStream out;public PrintStream debug;public volatile double score=0;public volatile int testCaseCount=-1;public volatile int testCaseIndex;public volatile double progress=0;public void runSubmission(){runSubmission(false);}public void runSubmission(boolean debug){runSubmission(System.in,System.out,debug);}public void runSubmission(InputStream in,PrintStream out){runSubmission(in,out,false);}public void runSubmission(InputStream in,PrintStream out,boolean debug){runSubmission(in,out,debug?System.err:new VoidPrintStream());}public void runSubmission(InputStream in,OutputStream out,OutputStream debug){this.in=in;this.sc=new FastScanner(this.in);this.out=new PrintStream(out);this.debug=debug instanceof VoidOutputStream||debug instanceof VoidPrintStream?new VoidPrintStream():new DebugPrintStream(debug);ContestType type=getType();testCaseCount=type.testCaseCount;init();if(testCaseCount<=0){testCaseCount=sc.nextInt();sc.nextLine();}testCaseIndex=0;for(testCaseIndex=1;testCaseIndex<=testCaseCount;testCaseIndex++){progress=0;this.out.printf(type.caseString,testCaseIndex,testCaseCount);testCase();}}private class DebugPrintStream extends PrintStream{public DebugPrintStream(OutputStream debug){super(debug);}private Object conv(Object obj){if(obj instanceof byte[])return Arrays.toString((byte[])obj);else if(obj instanceof char[])return Arrays.toString((char[])obj);else if(obj instanceof short[])return Arrays.toString((short[])obj);else if(obj instanceof int[])return Arrays.toString((int[])obj);else if(obj instanceof long[])return Arrays.toString((long[])obj);else if(obj instanceof float[])return Arrays.toString((float[])obj);else if(obj instanceof double[])return Arrays.toString((double[])obj);else if(obj instanceof boolean[])return Arrays.toString((int[])obj);else if(obj instanceof Object[])return Arrays.deepToString((Object[])obj);else return obj;}public void print(Object obj){super.print(conv(obj));}public void println(Object obj){super.println(conv(obj));}}public ContestType getType(){return getType(getClass());}public static ContestType getType(Class<?extends AbstractSubmission>clss){return getAnnotation(clss).value();}private static ContestSubmission getAnnotation(Class<?extends AbstractSubmission>clss){if(!clss.isAnnotationPresent(ContestSubmission.class)){throw new RuntimeException("ContestSubmission annotation not present on class "+clss.getCanonicalName()+"!");}return clss.getAnnotation(ContestSubmission.class);}public abstract void testCase();public abstract void init();};

@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.TYPE)@interface CacheVersion{int value();};

@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.TYPE)@interface ContestSubmission{ContestType value();};

enum ContestType{PLAIN("",-1),ETH_JUDGE("",-1,null,false,false,6),GOOGLE("Case #%d: ",-1),GOOGLE_JAM("Case #%d: ",-1,"Solution.java",false,false,8),GOOGLE_JAM_INTERACTIVE("",-1,"Solution.java",false,false,8),FACEBOOK("Case #%d: ",-1),BLOOMBERG("",1,"Problem.java",false,false,8),SINGLE_TESTCASE("",1),OPTIMIZER("",1,null,false,false,8,true),HACKERRANK("",1,"Solution.java",false,false,8),CODEFORCES("",1,"Solution.java",false,false,8);public int testCaseCount;public String caseString;public String launcher;public boolean disableCompression;public boolean keepUnusedDependencies;public int javaVersion;public boolean isOptimizer;ContestType(String caseString,int testCaseCount,String launcher,boolean disableCompression,boolean keepUnusedDependencies,int javaVersion,boolean isOptimizer){this.caseString=caseString;this.testCaseCount=testCaseCount;this.launcher=launcher;this.disableCompression=disableCompression;this.javaVersion=javaVersion;this.keepUnusedDependencies=keepUnusedDependencies;this.isOptimizer=isOptimizer;}ContestType(String a1,int a2,String a3,boolean a4,boolean a5,int a6){this(a1,a2,a3,a4,a5,a6,false);}ContestType(String a1,int a2){this(a1,a2,null,false,false,8);}};

class FastScanner{private static String spaceDelimiters=" \t\n\r\f";private BufferedReader buffer;private StringTokenizer tokenizer;private InputStream stream;public FastScanner(InputStream stream){this.stream=stream;}public String nextLine(){if(this.buffer==null)this.buffer=new BufferedReader(new InputStreamReader(stream));while(tokenizer==null){try{tokenizer=new StringTokenizer(buffer.readLine()+"\n");}catch(IOException e){throw new RuntimeException("IO exception occured!",e);}}String res=tokenizer.nextToken("");if(!res.endsWith("\n"))throw new RuntimeException("waddaheq just heppenenened");res=res.substring(0,res.length()-1);if(res.contains("\n"))throw new RuntimeException("oke wat lamo");tokenizer=null;return res;}public String next(){if(this.buffer==null)this.buffer=new BufferedReader(new InputStreamReader(stream));while(tokenizer==null||!tokenizer.hasMoreTokens()){try{tokenizer=new StringTokenizer(buffer.readLine()+"\n");}catch(IOException e){throw new RuntimeException("IO exception occured!",e);}}return tokenizer.nextToken(spaceDelimiters);}public BigDecimal nextBigDecimal(){return new BigDecimal(next());}public BigInteger nextBigInteger(){return new BigInteger(next());}public int nextInt(){return Integer.parseInt(next());}public long nextLong(){return Long.parseLong(next());}public double nextDouble(){return Double.parseDouble(next());}};

@Retention(RetentionPolicy.SOURCE)@Target(ElementType.METHOD)@interface O{String value();};

@Target(ElementType.FIELD)@Retention(RetentionPolicy.RUNTIME)@interface Optimize{long imin()default 0;long imax()default 100;double fmin()default 0;double fmax()default 1;};

class VoidOutputStream extends OutputStream{public void write(int b){return;}public void write(byte b[]){return;}public void write(byte b[],int off,int len){return;}};

class VoidPrintStream extends PrintStream{public VoidPrintStream(){super(new VoidOutputStream());}public void write(int b){return;}public void print(char[]buf){return;}public void print(String s){return;}public void print(Object obj){return;}public void println(char[]buf){return;}public void println(String s){return;}public void println(Object obj){return;}public PrintStream format(Locale l,String s,Object...objs){return this;}public PrintStream format(String s,Object...objs){return this;}};