main(){
  inversion();
}
inversion(){
  List<int> list = [2,3,8,6,1];
  for(int i = 0; i < list.length;i++){
    for(int j = i+1; j<list.length;j++){
      if(i<j&& list[i]>list[j]){
                print("pair {$i,$j} is an inversion");
        print("${list[i]} and ${list[j]} is an inversion");

      }
    }
  }
  }