Problem:
Deque

For a dynamic array $A = \{a_0, a_1, ...\}$ of integers, perform a sequence of the following operations:

push($d$, $x$): Add element $x$ at the begining of $A$, if $d = 0$. Add element $x$ at the end of $A$, if $d = 1$.

randomAccess($p$): Print element $a_p$.

pop($d$): Delete the first element of $A$, if $d = 0$. Delete the last element of $A$, if $d = 1$.

$A$ is a 0-origin array and it is empty in the initial state.

Input

The input is given in the following format.

$q$
$query_1$
$query_2$
:
$query_q$

Each query $query_i$ is given by

0 $d$ $x$

or

1 $p$

or

2 $d$

where the first digits 0, 1 and 2 represent push, randomAccess and pop operations respectively.

randomAccess and pop operations will not be given for an empty array.

Output

For each randomAccess, print $a_p$ in a line.

Constraints

$1 \leq q \leq 400,000$

$0 \leq p < $ the size of $A$

$-1,000,000,000 \leq x \leq 1,000,000,000$

Sample Input 1

11
0 0 1
0 0 2
0 1 3
1 0
1 1
1 2
2 0
2 1
0 0 4
1 0
1 1

Sample Output 1

2
1
3
4
1

Solution in C (judge verdict: Time Limit Exceeded)

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

int push(long *A, long x, int len, int d) {
    int i;

    if (d==1) {
        A[len]=x;
        return len+1;
    } else {
        for (i=len-1;i>=0;i--) {
            A[i+1]=A[i];
        }
        A[0]=x;
        return len+1;
    }
}

int pop(long *A, int len, int d) {
    int i;

    if (d==1) {
        A[len] = '\0';
        return len-1;
    } else {
        for (i=0;i<len;i++) {
            A[i]=A[i+1];
        }
        A[len]='\0';
        return len-1;
    }
}

void randomAccess(long *A, int p) {
    printf("%ld\n", A[p]);
}

int main(void) {
    long *A, x;
    int i, p, q, d, query, len=0;

    scanf("%d", &q);
    A=(long *)malloc(sizeof(long)*q);
    memset(A, '\0', sizeof(long)*q);

    for (i=0; i<q; i++) {
        scanf("%d", &query);
        if (query==0) {
            scanf("%d %ld", &d, &x);
            len=push(A, x, len, d);
        } else if (query==1) {
            scanf("%d", &p);
            randomAccess(A, p);
        } else if (query==2) {
            scanf("%d", &d);
            len=pop(A, len, d);
        }
    }
    free(A);
    return 0;
}