import java.io.File;
import java.io.FileNotFoundException; 
import java.util.Scanner;





class DayOne {
        public static void main( String[] args) {
            int count = 0;
            int count2 = 0;
            int[] numbers;
            int[] solutions;
            solutions = new int[20];
            numbers = new int[500];
            try {
                File inputFile = new File("input.txt");
                Scanner readFile = new Scanner(inputFile);
                while (readFile.hasNextLine()) {
                    numbers[count] = readFile.nextInt();
                    count ++;
                }
                readFile.close();
            } catch (FileNotFoundException e) {
                System.out.println("crap");
            }
            
            for (int i = 0; i < count; i++){
                for (int j = 0; j < count; j++){
                    for (int k = 0; k < count; k++){
                        if (numbers[i] + numbers[j] + numbers[k] == 2020) {
                        solutions[count2] = numbers[i];
                        solutions[count2+1] = numbers[j];
                        solutions[count2+2] = numbers[k];
                        count2 = count2 + 3;
                    }
                }
                }
            }
            System.out.println(solutions[0] * solutions[1] * solutions[2]);
            






        }
}