C.A.T

import java.util.Arrays;
import java.util.Scanner;

public class Pr7CondenseArrayToNumber {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int result = 0;
        int[] num = Arrays
                .stream(scanner.nextLine().split(" "))
                .mapToInt(e -> Integer.parseInt(e))
                .toArray();
        int count = num.length;
        if (num.length == 1) {
            System.out.println(num[0]);
        } else {
            while (count > 1) {
                for (int i = 0; i < num.length - 1; i++) {
                    num[i] = num[i] + num[i + 1];
                    //System.out.print(num[i] + " ");
                    result = num[i];
                }
                num = Arrays.copyOf(num, num.length - 1);
                count--;
                //if (count > 1) System.out.print("-> ");
            }
            System.out.println(result);
        }
    }