import java.io.*;
import java.util.Scanner;
 
public class Main {
 
  public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  }
} import java.io.*; io.* java import java.util.Scanner; Scanner java.util public class Main {
 
  public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  }
} Main public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  } main {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  } try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    } catch (Exception e) {     
      System.out.print("error");
    } Exception e {     
      System.out.print("error");
    } System.out.print("error") System.out.print System.out System System.out "error" {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } Scanner scan   = new Scanner(System.in); scan new Scanner(System.in) Long    tax1   = Long.parseLong(scan.next()); tax1 Long.parseLong(scan.next()) Long.parseLong Long scan.next() scan.next scan Long    tax2   = Long.parseLong(scan.next()); tax2 Long.parseLong(scan.next()) Long.parseLong Long scan.next() scan.next scan double  price1 = tax1/0.08; price1 tax1/0.08 tax1 0.08 double  price2 = tax2/0.1; price2 tax2/0.1 tax2 0.1 double  result = -1.0; result -1.0 1.0 if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      } price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1 price1 >= price2 price1 price2 Math.ceil(price1) < (tax2+1)/0.1 Math.ceil(price1) Math.ceil Math price1 (tax2+1)/0.1 (tax2+1) tax2 1 0.1 {
        result = Math.ceil(price1);
      } result = Math.ceil(price1) result Math.ceil(price1) Math.ceil Math price1 if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      } price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08 price2 >= price1 price2 price1 Math.ceil(price2) < (tax1+1)/0.08 Math.ceil(price2) Math.ceil Math price2 (tax1+1)/0.08 (tax1+1) tax1 1 0.08 {
        result = Math.ceil(price2);
      } result = Math.ceil(price2) result Math.ceil(price2) Math.ceil Math price2 System.out.println((int)result) System.out.println System.out System System.out (int)result String[] args args public class Main {
 
  public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  }
} public class Main {
 
  public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  }
} Main
import java.io.*;
import java.util.Scanner;
 
public class Main {
 
  public static void main(String[] args) {
 
    try {
      Scanner scan   = new Scanner(System.in);      
      Long    tax1   = Long.parseLong(scan.next());
      Long    tax2   = Long.parseLong(scan.next());
      double  price1 = tax1/0.08;
      double  price2 = tax2/0.1;
      double  result = -1.0;
      
      if (price1 >= price2 && Math.ceil(price1) < (tax2+1)/0.1) {
        result = Math.ceil(price1);
      }
      
      if (price2 >= price1 && Math.ceil(price2) < (tax1+1)/0.08) {
        result = Math.ceil(price2);
      }
      
      System.out.println((int)result);
      
    } catch (Exception e) {     
      System.out.print("error");
    }
  }
}
