2derevo
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


struct tree{
    int key;
    struct tree *left, *right, *parent;
};

int cmp(const void *x1, const void *x2){
    return (*(int*)x1 - *(int*)x2);
}

struct tree *distrib(int *a, int n){
    if (n <= 0) return NULL;
    static int KEK;
    struct tree *non;
    non = malloc(sizeof(struct tree));
    if (!KEK) {
        qsort(a, n, sizeof(int), cmp);
        KEK = 1;
        non -> parent = NULL;
    }

    if (n == 1) {
        printf("%d \n", a[0]);
        non -> left = non -> right = NULL;
        non -> key = a[0];
        return non;
    }
    int t = n / 2 - (1 - n&1);
    non -> key = a[t];
    non -> left = distrib(a, t);
    non -> right = distrib(a + t + 1, n - t - 1);
    if (non -> left)
        non -> left -> parent = non;

    if (non -> right)
        non -> right -> parent = non;

    return non;
};

void print(struct tree * t) {
    if (!t) return;
    print(t->left);
    printf("(%d)\n", t -> key);
    print(t->right);
}

int main(void){
    int n;
    scanf("%d", &n);
    int a[n];
    for (int i = 0; i < n; ++i)
        scanf("%d", &a[i]);

    print( distrib(a, n) );
    return 0;
}