Problem:
Score : 600 points

Problem Statement

Snuke has an integer sequence, a, of length N. The i-th element of a (1-indexed) is a_{i}.

He can perform the following operation any number of times:

Operation: Choose integers x and y between 1 and N (inclusive), and add a_x to a_y.

He would like to perform this operation between 0 and 2N times (inclusive) so that a satisfies the condition below. Show one such sequence of operations.
It can be proved that such a sequence of operations always exists under the constraints in this problem.

Condition: a_1 \leq a_2 \leq ... \leq a_{N}

Constraints

2 \leq N \leq 50

-10^{6} \leq a_i \leq 10^{6}

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 ... a_{N}

Output

Let m be the number of operations in your solution. In the first line, print m.
In the i-th of the subsequent m lines, print the numbers x and y chosen in the i-th operation, with a space in between.
The output will be considered correct if m is between 0 and 2N (inclusive) and a satisfies the condition after the m operations.

Sample Input 1

3
-2 5 -1

Sample Output 1

2
2 3
3 3

After the first operation, a = (-2,5,4).

After the second operation, a = (-2,5,8), and the condition is now satisfied.

Sample Input 2

2
-1 -3

Sample Output 2

1
2 1

After the first operation, a = (-4,-3) and the condition is now satisfied.

Sample Input 3

5
0 0 0 0 0

Sample Output 3

0

The condition is satisfied already in the beginning.

Solution in PyPy3 (2.4.0) (judge verdict: Wrong Answer)

from collections import deque
import sys
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))
mod = 10**9 + 7
inf = float('inf')

N = I()
a = LI()
ansC = []
ans = int(0)

amax = a[0]; amaxL = int(0)
amin = a[0]; aminL = int(0)
k = []
kmin = []
k = deque()
kmin = deque()
for i in range(N-1):
    if a[i]>a[i+1]:
        k.append(i+1)
        kmin.append(i)
    if amax<=a[i+1]:
        amax = a[i+1]
        amaxL = i+1
    if amin>=a[i+1]:
        amin = a[i+1]
        aminL = i+1

if amax+amin>=0:
    while k:
        for i in k:
            a[i] += amax
            ansC.append([amaxL+1,i+1])
        amax = max(a)
        k = deque()
        for i in range(N - 1):
            if a[i] > a[i + 1]:
                k.append(i + 1)
else:
    while kmin:
        for i in kmin:
            a[i] += amin
            ansC.append([aminL+1,i+1])
        amin = min(a)
        kmin = deque()
        for i in range(N - 1):
            if a[i] > a[i + 1]:
                kmin.append(i + 1)

#print(a)
ans = len(ansC)
print(ans)
if ansC:
    for v in ansC:
        print(" ".join(map(str,v)))