n=int(input())
ai=[[a,i] for i,a in enumerate(map(int,input().split()))]
ai.sort()
ans=[]
for j in range(n):
    while 1:
        j,k=ai[j][1],j
        ai[k][1]=-1
        if ai[j][1] == -1:break
        ans.append((j,k))
print(len(ans),flush=True)
for j,k in ans:print(j,k,flush=True)
input()