N = int(input())
a = list(map(int, input().split()))
query = []
append = query.append
flag = True

while flag:
    flag = False

    for i in range(N-1):
        if a[i] > a[i+1]:
            a[i], a[i+1] = a[i+1], a[i]
            append((i, i+1))
            flag = True

print(len(query))
for q in query:
    print(" ".join(map(str, q)))
input()