Problem:
Score : 300 points

Problem Statement

Find the price of a product before tax such that, when the consumption tax rate is 8 percent and 10 percent, the amount of consumption tax levied on it is A yen and B yen, respectively. (Yen is the currency of Japan.)

Here, the price before tax must be a positive integer, and the amount of consumption tax is rounded down to the nearest integer.

If multiple prices satisfy the condition, print the lowest such price; if no price satisfies the condition, print -1.

Constraints

1 \leq A \leq B \leq 100

A and B are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

If there is a price that satisfies the condition, print an integer representing the lowest such price; otherwise, print -1.

Sample Input 1

2 2

Sample Output 1

25

If the price of a product before tax is 25 yen, the amount of consumption tax levied on it is:

When the consumption tax rate is 8 percent: \lfloor 25 \times 0.08 \rfloor = \lfloor 2 \rfloor = 2 yen.

When the consumption tax rate is 10 percent: \lfloor 25 \times 0.1 \rfloor = \lfloor 2.5 \rfloor = 2 yen.

Thus, the price of 25 yen satisfies the condition. There are other possible prices, such as 26 yen, but print the minimum such price, 25.

Sample Input 2

8 10

Sample Output 2

100

If the price of a product before tax is 100 yen, the amount of consumption tax levied on it is:

When the consumption tax rate is 8 percent: \lfloor 100 \times 0.08 \rfloor = 8 yen.

When the consumption tax rate is 10 percent: \lfloor 100 \times 0.1 \rfloor = 10 yen.

Sample Input 3

19 99

Sample Output 3

-1

There is no price before tax satisfying this condition, so print -1.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;

class Main{
	
	public static void main(String args[]){
      
	  Scanner scanner = new Scanner(System.in);
      String input = scanner.nextLine();
      
	  String nums[] = input.split(" ");
	  
	  // double eight = 8 / 100;
	  // double ten = 10 / 100;
	  
	  // long A = Long.parseLong(nums[0]);
	  // long B = Long.parseLong(nums[1]);
	  // long sum = Long.parseLong(nums[2]);
	  int A = Integer.parseInt(nums[0]);
	  int B = Integer.parseInt(nums[1]);
	  
	  int ansA = (A * 8) / 100;
	  if((A * 8) % 100 > 0){
	  	ansA++;
	  }
	  
	  int ansB = B / 10;
	  if((B % 10) > 0){
	    ansB++;
	  }
	  
	  if(ansA > ansB){
	    System.out.println(ansA);
	  }else{
	    System.out.println(ansB);
	  }
	  
	}
}