N = int(input())
A = list(map(int, input().split()))
S = []
T = 0
for i in range(2*N):
    if i < N:
        T -= A[i]
    else:
        T += A[i]
    S.append([A[i], i+1]) 
sS = sorted(S) 

print(T)
for i in range(N):
    print(sS[i][1], sS[i+N][1])