Problem: For a dictionary $M$ that stores elements formed by a pair of a string key and an integer value, perform a sequence of the following operations. Note that each key in $M$ must be unique.

* insert($key$, $x$): Insert an element formed by a pair of $key$ and $x$ to $M$.
* get($key$): Print the value with the specified $key$. Print 0 if there is no such element.
* delete($key$): Delete the element with the specified $key$.
* dump($L$, $R$): Print all elements formed by a pair of the key and the value such that the key is greater than or equal to $L$ and less than or equal to $R$ in lexicographic order.

Constraints

* $1 \leq q \leq 200,000$
* $1 \leq x \leq 1,000,000,000$
* $1 \leq $ length of $key$ $ \leq 20$
* $key$ consists of lower-case letters
* $L \leq R$ in lexicographic order
* The total number of elements printed by dump operations does not exceed $1,000,000$

Input

The input is given in the following format.


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


Each query $query_i$ is given by


0 $key$ $x$


or


1 $key$


or


2 $key$


or


3 $L$ $R$


where the first digits 0, 1, 2 and 3 represent insert, get, delete and dump operations.

Output

For each get operation, print the corresponding value.
For each dump operation, print the corresponding elements formed by a pair of the key and the value. For the dump operation, print the elements (a pair of key and value separated by a space character) in ascending order of the keys.

Example

Input

9
0 blue 4
0 red 1
0 white 5
1 red
1 blue
2 red
1 black
1 red
3 w z


Output

1
4
0
0
white 5

Solution (in PYTHON3):

Solution:
from collections import defaultdict
import bisect

def main():
    q = int(input())
    d = defaultdict(int)

    inserted_flag = False
    sorted_keys = None

    for _ in range(q):
        para = input().split()

        if para[0] == "0":
            d[para[1]] = int(para[2])
            inserted_flag = True

        elif para[0] == "1":
            if para[1] in d.keys():
                print(d[para[1]])
            else:
                print("0")

        elif para[0] == "2":
            if para[1] in d.keys():
                del d[para[1]]
                inserted_flag = True
            
        elif para[0] == "3":
            if sorted_keys is None:
                sorted_keys = sorted(d.keys())

            if inserted_flag:
                sorted_keys = sorted(d.keys())
                inserted_flag = False

            l = bisect.bisect_left(sorted_keys, para[1])
            r = bisect.bisect_right(sorted_keys, para[2])

            for i in range(l, r):
                print("{} {}".format(sorted_keys[i], d[sorted_keys[i]]))

main()