Untitled

#python
def heapify(arr, cnt):
    pair = []
    flg = 0
    for i in range(len(arr)-1, 0, -1):
        if arr[i] < arr[(i-1)//2]:
            flg = 1
            if len(pair) == 0:
                pair = [i, (i-1)//2]
            elif (i-1)//2 == pair[1]:
                if arr[i] < arr[pair[0]]:
                    pair[0] = i
    if flg:
        arr[pair[0]], arr[pair[1]] = arr[pair[1]], arr[pair[0]]
        cnt += 1
        ans = heapify(arr, cnt)
        return [ans[0], ans[1], ans[2] + [[pair[1], pair[0]]]]
    else:
        return [arr, cnt, []]

n = int(input())
arr = list(map(int, input().split()))
ans = heapify(arr, 0)
ans[2] = ans[2][::-1]
print(ans[1])
print('\n'.join([" ".join(map(str, ans[2][i])) for i in range(len(ans[2]))]))