#include <bits/stdc++.h>
using namespace std;

signed main(){
  int N; cin >> N;
  vector< int > A( N );
  for( int i = 0; i < N; ++i )
    cin >> A[ i ];
  vector< pair< int, int > > ans;
  for( int i = 0; i < N; ++i )
    for( int j = 0; j + 1 < N; ++j )
      if( A[ j ] > A[ j + 1 ] )
        swap( A[ j ], A[ j + 1 ] ),
        ans.emplace_back( j, j + 1 );
  if( ans.empty() )
    cout << -1 << endl;
  else{
    for( int i = 0; i < ans.size(); ++i )
      cout << ans[ i ].first << " " << ans[ i ].second << endl;
  }
  int dummy; cin >> dummy;
  return 0;
}