Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3

import sys
from typing import Any, Callable, Deque, Dict, List, Mapping, Optional, Sequence, Set, Tuple, TypeVar, Union
# import time
# import math, cmath
# import numpy as np
# import scipy.sparse.csgraph as cs            # csgraph_from_dense(ndarray, null_value=inf), bellman_ford(G, return_predecessors=True), dijkstra, floyd_warshall
# import random                                # random, uniform, randint, randrange, shuffle, sample
# import string                                # ascii_lowercase, ascii_uppercase, ascii_letters, digits, hexdigits
# import re                                    # re.compile(pattern) => ptn obj; p.search(s), p.match(s), p.finditer(s) => match obj; p.sub(after, s)
# from bisect import bisect_left, bisect_right # bisect_left(a, x, lo=0, hi=len(a)) returns i such that all(val<x for val in a[lo:i]) and all(val>-=x for val in a[i:hi]).
# from collections import deque                # deque class. deque(L): dq.append(x), dq.appendleft(x), dq.pop(), dq.popleft(), dq.rotate()
# from collections import defaultdict          # subclass of dict. defaultdict(facroty)
# from collections import Counter              # subclass of dict. Counter(iter): c.elements(), c.most_common(n), c.subtract(iter)
# from datetime import date, datetime          # date.today(), date(year,month,day) => date obj; datetime.now(), datetime(year,month,day,hour,second,microsecond) => datetime obj; subtraction => timedelta obj
# from datetime.datetime import strptime       # strptime('2019/01/01 10:05:20', '%Y/%m/%d/ %H:%M:%S') returns datetime obj
# from datetime import timedelta               # td.days, td.seconds, td.microseconds, td.total_seconds(). abs function is also available.
# from copy import copy, deepcopy              # use deepcopy to copy multi-dimentional matrix without reference
# from functools import reduce                 # reduce(f, iter[, init])
# from functools import lru_cache              # @lrucache ...arguments of functions should be able to be keys of dict (e.g. list is not allowed)
# from heapq import heapify, heappush, heappop # built-in list. heapify(L) changes list in-place to min-heap in O(n), heappush(heapL, x) and heappop(heapL) in O(lgn).
# from heapq import _heapify_max, _heappop_max, _siftdown_max
# from heapq import nlargest, nsmallest        # nlargest(n, iter[, key]) returns k-largest-list in O(n+klgn).
# from itertools import count, cycle, repeat   # count(start[,step]), cycle(iter), repeat(elm[,n])
# from itertools import groupby                # [(k, list(g)) for k, g in groupby('000112')] returns [('0',['0','0','0']), ('1',['1','1']), ('2',['2'])]
# from itertools import starmap                # starmap(pow, [[2,5], [3,2]]) returns [32, 9]
# from itertools import product, permutations  # product(iter, repeat=n), permutations(iter[,r])
# from itertools import combinations, combinations_with_replacement
# from itertools import accumulate             # accumulate(iter[, f])
# from operator import itemgetter              # itemgetter(1), itemgetter('key')
# from fractions import Fraction               # Fraction(a, b) => a / b ∈ Q. note: Fraction(0.1) do not returns Fraciton(1, 10). Fraction('0.1') returns Fraction(1, 10)



def main():
    Num = Union[int, float]
    mod = 1000000007                # 10^9+7
    inf = float('inf')              # sys.float_info.max = 1.79e+308
    # inf = 2 ** 63 - 1             # (for fast JIT compile in PyPy) 9.22e+18
    sys.setrecursionlimit(10**6)    # 1000 -> 1000000
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def isp():   return input().split()
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())
    # def _heappush_max(h, item): h.append(item); _siftdown_max(h, 0, len(h)-1)


    def solve(L):
        M = 0
        command = []
        if L[-1] >= 0:
            # 全て正
            command.append([L[-1], L[0]])
            neg = L[-1] - L[0]
            L = L[1:-1]
            for i in range(1, len(L)):
                command.append([neg, L[i]])
                neg -= L[i]
            # 最後に正 - 負
            command.append([L[0], neg])
            M = L[0] - neg
        elif L[0] <= 0:
            # 全て負
            command.append([L[0], L[-1]])
            pos = L[0] - L[-1]            
            L = L[1:-1]
            for i in range(len(L)):
                command.append([pos, L[i]])
                pos -= L[i]
            M = pos
        else:
            for i in range(len(L)):
                if L[i] < 0:
                    break
            neg = L[i]
            for j in range(1, i):
                command.append([neg, L[j]])
                neg -= L[j]
            L = [L[0], neg] + L[i+1:]
            M = L[0]
            for i in range(1, len(L)):
                command.append([M, L[i]])
                M -= L[i]
        return M, command
                

    
    
    n = ii()
    L = lmi()
    L.sort(reverse=True)
    M, command = solve(L)
    print(M)
    for x, y in command:
        print(f"{x} {y}")


if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys


def main():
    def input(): return sys.stdin.readline().rstrip()
    def ii():    return int(input())
    def isp():   return input().split()
    def mi():    return map(int, input().split())
    def mi_0():  return map(lambda x: int(x)-1, input().split())
    def lmi():   return list(map(int, input().split()))
    def lmi_0(): return list(map(lambda x: int(x)-1, input().split()))
    def li():    return list(input())



    def solve(L):
        M = 0
        command = []
        if L[-1] >= 0:
            # 全て正
            if len(L) > 2:
                command.append([L[-1], L[0]])
                neg = L[-1] - L[0]
                L = L[1:-1]
                for i in range(1, len(L)):
                    command.append([neg, L[i]])
                    neg -= L[i]
                # 最後に正 - 負
                command.append([L[0], neg])
                M = L[0] - neg
            else:
                command.append([L[0], L[1]])
                M = L[0] - L[1]
        elif L[0] <= 0:
            # 全て負
            command.append([L[0], L[-1]])
            pos = L[0] - L[-1]            
            L = L[1:-1]
            for i in range(len(L)):
                command.append([pos, L[i]])
                pos -= L[i]
            M = pos
        else:
            for i in range(len(L)):
                if L[i] < 0:
                    break
            neg = L[i]
            for j in range(1, i):
                command.append([neg, L[j]])
                neg -= L[j]
            L = [L[0], neg] + L[i+1:]
            M = L[0]
            for i in range(1, len(L)):
                command.append([M, L[i]])
                M -= L[i]
        return M, command
                

    
    
    n = ii()
    L = lmi()
    L.sort(reverse=True)
    M, command = solve(L)
    print(M)
    for x, y in command:
        print(f"{x} {y}")


if __name__ == "__main__":
    main()