Buggy python submission (verdict: Runtime Error):
import heapq
n=int(input())
Ans=[]
A=[int(i) for i in input().split()]
A.sort()
if A[0]>=0:
  Ans=[]
  heapq.heapify(A)
  for i in range(n-2):
    a1=heapq.heappop(A)
    a2=heapq.heappop(A)
    Ans.append([a1,a2])
    heapq.heappush(A,a1-a2)
  a1=heapq.heappop(A)
  a2=heapq.heappop(A)
  Ans.append([a2,a1])
  print(a2-a1)
  for i in range(n-1):
    print(*Ans[i])

elif A[-1]<=0:
  Ans=[]
  AA=[]
  for i in range(n):
    AA.append(-A[i])
  heapq.heapify(AA)
  for i in range(n-2):
    a1=heapq.heappop(AA)
    a2=heapq.heappop(AA)
    Ans.append([-a1,-a2])
    heapq.heappush(A,-(a2-a1))
  a1=heapq.heappop(A)
  a2=heapq.heappop(A)
  Ans.append([a2,-a1])
  print(a2+a1)
  for i in range(n-1):
    print(*Ans[i])
else:    
  Ap,Az,Am=[],[],[]
  for i in range(n):
    if A[i]>0:
      Ap.append(A[i])
    elif A[i]==0:
      Az.append(A[i])
    else:
      Am.append(-A[i])
  Ap.sort()
  Am.sort()
  pp,mm=Ap.pop(),Am.pop()
  heapq.heapify(Ap)
  heapq.heapify(Am)

  while len(Am)>=1:
    am=heapq.heappop(Am)
    Ans.append([pp,-am])
    pp+=am
  while len(Ap)>=1:
    ap=heapq.heappop(Ap)
    Ans.append([-mm,ap])
    mm+=ap
  for i in range(len(Az)):
    Ans.append([pp,0])
  Ans.append([pp,-mm])
  print(pp+mm)
  for i in range(len(Ans)):
    print(*Ans[i])

Fixed submission:
import heapq
n=int(input())
Ans=[]
A=[int(i) for i in input().split()]
A.sort()
if A[0]>=0:
  Ans=[]
  heapq.heapify(A)
  for i in range(n-2):
    a1=heapq.heappop(A)
    a2=heapq.heappop(A)
    Ans.append([a1,a2])
    heapq.heappush(A,a1-a2)
  a1=heapq.heappop(A)
  a2=heapq.heappop(A)
  Ans.append([a2,a1])
  print(a2-a1)
  for i in range(n-1):
    print(*Ans[i])

elif A[-1]<=0:
  Ans=[]
  AA=[]
  for i in range(n):
    AA.append(-A[i])
  heapq.heapify(AA)
  for i in range(n-2):
    a1=heapq.heappop(AA)
    a2=heapq.heappop(AA)
    Ans.append([-a1,-a2])
    heapq.heappush(AA,-(a2-a1))
  a1=heapq.heappop(AA)
  a2=heapq.heappop(AA)
  Ans.append([max(-a2,-a1),min(-a2,-a1)])
  print(max(-a2,-a1)-min(-a2,-a1))
  for i in range(n-1):
    print(*Ans[i])
else:    
  Ap,Az,Am=[],[],[]
  for i in range(n):
    if A[i]>0:
      Ap.append(A[i])
    elif A[i]==0:
      Az.append(A[i])
    else:
      Am.append(-A[i])
  Ap.sort()
  Am.sort()
  pp,mm=Ap.pop(),Am.pop()
  heapq.heapify(Ap)
  heapq.heapify(Am)

  while len(Am)>=1:
    am=heapq.heappop(Am)
    Ans.append([pp,-am])
    pp+=am
  while len(Ap)>=1:
    ap=heapq.heappop(Ap)
    Ans.append([-mm,ap])
    mm+=ap
  for i in range(len(Az)):
    Ans.append([pp,0])
  Ans.append([pp,-mm])
  print(pp+mm)
  for i in range(len(Ans)):
    print(*Ans[i])

Buggy python submission (verdict: Runtime Error):
import heapq
n=int(input())
A=[int(i) for i in input().split()]
Ap,Az,Am=[],[],[]
for i in range(n):
  if A[i]>0:
    Ap.append(A[i])
  elif A[i]==0:
    Az.append(A[i])
  else:
    Am.append(-A[i])
Ap.sort()
Am.sort()
pp,mm=Ap.pop(),Am.pop()
heapq.heapify(Ap)
heapq.heapify(Am)
Ans=[]
while len(Am)>=1:
  am=heapq.heappop(Am)
  Ans.append([pp,-am])
  pp+=am
while len(Ap)>=1:
  ap=heapq.heappop(Ap)
  Ans.append([-mm,ap])
  mm+=ap
Ans.append([pp,-mm])
print(pp+mm)
for i in range(len(Ans)):
  print(*Ans[i])

Fixed submission:
import heapq
n=int(input())
Ans=[]
A=[int(i) for i in input().split()]
A.sort()
if A[0]>=0:
  Ans=[]
  heapq.heapify(A)
  for i in range(n-2):
    a1=heapq.heappop(A)
    a2=heapq.heappop(A)
    Ans.append([a1,a2])
    heapq.heappush(A,a1-a2)
  a1=heapq.heappop(A)
  a2=heapq.heappop(A)
  Ans.append([a2,a1])
  print(a2-a1)
  for i in range(n-1):
    print(*Ans[i])

elif A[-1]<=0:
  Ans=[]
  AA=[]
  for i in range(n):
    AA.append(-A[i])
  heapq.heapify(AA)
  for i in range(n-2):
    a1=heapq.heappop(AA)
    a2=heapq.heappop(AA)
    Ans.append([-a1,-a2])
    heapq.heappush(AA,-(a2-a1))
  a1=heapq.heappop(AA)
  a2=heapq.heappop(AA)
  Ans.append([max(-a2,-a1),min(-a2,-a1)])
  print(max(-a2,-a1)-min(-a2,-a1))
  for i in range(n-1):
    print(*Ans[i])
else:    
  Ap,Az,Am=[],[],[]
  for i in range(n):
    if A[i]>0:
      Ap.append(A[i])
    elif A[i]==0:
      Az.append(A[i])
    else:
      Am.append(-A[i])
  Ap.sort()
  Am.sort()
  pp,mm=Ap.pop(),Am.pop()
  heapq.heapify(Ap)
  heapq.heapify(Am)

  while len(Am)>=1:
    am=heapq.heappop(Am)
    Ans.append([pp,-am])
    pp+=am
  while len(Ap)>=1:
    ap=heapq.heappop(Ap)
    Ans.append([-mm,ap])
    mm+=ap
  for i in range(len(Az)):
    Ans.append([pp,0])
  Ans.append([pp,-mm])
  print(pp+mm)
  for i in range(len(Ans)):
    print(*Ans[i])