#include <iostream>
#include <fstream>
#include <iomanip>

using namespace std;

ifstream fin("pachete.in");
ofstream fout("pachete.out");
int n,v[101];
struct
{
    int m1,m2;
}mutare[201];
int main()
{
    int i,pozlib,j,aux,k=0;
    cin>>n;
    for(i=1; i<=n; i++)
        cin>>v[i];
    pozlib=n+1;
    for(i=1; i<=n; i++)
        if(v[i]!=i)
        {
            for(j=i+1; j<=n+1; j++)
                if(v[j]==i)
                {
                    aux=j; break;
                }
            if(i!=pozlib)
            {
                mutare[++k].m1=i;
                mutare[k].m2=pozlib;
                v[pozlib]=v[i];
            }
            mutare[++k].m1=aux;
            mutare[k].m2=i;
            pozlib=aux;

        }
    cout<<k<<'\n';
    for(i=1; i<=k; i++)
        cout<<mutare[i].m1<<" "<<mutare[i].m2<<'\n';
    return 0;
}