#include<bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define mp make_pair
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128; 
template<typename T,typename U>
T ceil(T x, U y) {return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>
T floor(T x, U y) {return (x>0?x/y:(x-y+1)/y);}
template<class T,class S>
bool chmax(T &a,const S b) {return (a<b?a=b,1:0);}
template<class T,class S>
bool chmin(T &a,const S b) {return (a>b?a=b,1:0);}
int popcnt(int x) {return __builtin_popcount(x);}
int popcnt(ll x)  {return __builtin_popcountll(x);}
int topbit(int x) {return (x==0?-1:31-__builtin_clz(x));}
int topbit(ll x)  {return (x==0?-1:63-__builtin_clzll(x));}
int lowbit(int x) {return (x==0?-1:__builtin_ctz(x));}
int lowbit(ll x)  {return (x==0?-1:__builtin_ctzll(x));}

#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
typedef pair<int,int> pii; 
typedef vector<int> vi;
typedef vector<pii> vp;
typedef tuple<int,int,int> tiii;
int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=4105;
int n,a1[N],a2[N];
vp p1,p2;

void merge(vp &p,int *a,int l,int r) {
  if(l==r) return;
  int x=l, y=r, z=0, mid=l;
  while(mid<=r&&a[mid]<a[mid+1]) ++mid;
  if(mid>r||mid==r&&a[r-1]<a[r]) return;
  static int b[N];
  rep(i,l,r) b[i]=a[i];
  sort(b+l,b+r+1), z=b[mid];
  while(x<=mid&&a[x]<=z) x++;
  while(y>mid&&a[y]>z) y--;
  //cout<<"  merge "<<l<<" "<<r<<' '<<x<<" "<<y<<" "<<z<<endl;
  //cout<<"     "; rep(i,l,r) cout<<a[i]<<" "; puts("");
  rep(i,0,mid-x) if(x+i<mid-i)
    p.eb(x+i,mid-i), swap(a[x+i],a[mid-i]);
  rep(i,0,y-mid-1) if(mid+1+i<y-i)
    p.eb(mid+1+i,y-i), swap(a[mid+1+i],a[y-i]);
  rep(i,0,mid-x)
    p.eb(x+i,y-i), swap(a[x+i],a[y-i]);
  merge(p,a,l,mid), merge(p,a,mid+1,r);
}
void work(vp &p,int *a,int l,int r) {
  if(l==r) return; int mid=l+r>>1;
  work(p,a,l,mid), work(p,a,mid+1,r);
  //cout<<"WORK "<<l<<" "<<r<<": "; rep(i,l,r) cout<<a[i]<<" "; puts("");
  merge(p,a,l,r);
  //cout<<"WORK "<<l<<" "<<r<<": "; rep(i,l,r) cout<<a[i]<<" "; puts("");
}

signed main() {   
  n=read();
  rep(i,1,n) a1[i]=read();
  rep(i,1,n) a2[i]=read();
  work(p1,a1,1,n);
  //rep(i,1,n) cout<<a1[i]<<" "; puts("");
  work(p2,a2,1,n);
  printf("%d\n",(int)(p1.size()+p2.size()));
  for(auto [x,y]:p1) printf("%d %d\n",x,y);
  reverse(p2.begin(),p2.end());
  for(auto [x,y]:p2) printf("%d %d\n",x,y);
  return 0;
}