#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fs_node.h"



long total_size(struct fs_node *node) {
    // TODO: implement this function
    (void) node;
    return 0;
}


int main(void) {
    int n;
    if (scanf("%d", &n) != 1) { n = 0; }
    long sizes[20];
    for (int i = 0; i < n; i++) { scanf("%ld", &sizes[i]); }
    struct fs_node root;
    strcpy(root.name, "root");
    root.is_directory = 1;
    root.num_children = 0;
    struct fs_node files[20];
    struct fs_node sub;
    struct fs_node last_file;
    if (n == 1) {
        files[0].is_directory = 0;
        files[0].size = sizes[0];
        root.children[0] = &files[0];
        root.num_children = 1;
    } else if (n > 1) {
        for (int i = 0; i < n - 1; i++) {
            files[i].is_directory = 0;
            files[i].size = sizes[i];
            root.children[i] = &files[i];
        }
        strcpy(sub.name, "sub");
        sub.is_directory = 1;
        sub.num_children = 1;
        last_file.is_directory = 0;
        last_file.size = sizes[n - 1];
        sub.children[0] = &last_file;
        root.children[n - 1] = &sub;
        root.num_children = n;
    }
    printf("%ld\n", total_size(&root));
    return 0;
}