import java.io.BufferedReader;
import java.io.FileReader;
import java.io.PrintWriter;

public class Main {

    public static void main(String[] args) {
        PrintWriter writer = new PrintWriter("costperm.out");

        BufferedReader bufferedReader = new BufferedReader(new FileReader("costperm.in"));

        String line = bufferedReader.readLine();

        int n = Integer.valueOf(line);

        line = bufferedReader.readLine();

        String[] args = line.split(" ");

        int[] numbers = new int[n];

        for(int i = 0; i < n; i++)
            numbers[i] = Integer.valueOf(args[i]);

        int cost = 0;

        for(int i = 0; i < n - 1; i++){
            for(int j = i + 1; j < n; j++){
                if(numbers[j] > numbers[i])
                    break;

                cost += numbers[j];
            }
        }

        writer.print(cost);
    }
}