var N, P, i, j, z: integer;
    arr: array[1..1000] of integer;
begin
    read(N);
    for i := 1 to N do
        read(arr[i]);
    P := 0;
    for i := 1 to N do
        for j := 1 to N - 1 do
            if arr[j] > arr[j + 1] then
            begin
                z := arr[j];
                arr[j] := arr[j + 1];
                arr[j + 1] := z;
                inc(P);
            end;
    writeln(P);
end.