Some FlightNumber values are missing (NaN). They should increase by 10 each row. Fill them in and make the column an integer column. Return the FlightNumber Series.

Input

            From_To  FlightNumber  RecentDelays              Airline
0      LoNDon_paris       10045.0      [23, 47]               KLM(!)
1      MAdrid_miLAN           NaN            []    <Air France> (12)
2  londON_StockhOlm       10065.0  [24, 43, 87]  (British Airways. )
3    Budapest_PaRis           NaN          [13]       12. Air France
4   Brussels_londOn       10085.0      [67, 32]          "Swiss Air"

Output

0    10045
1    10055
2    10065
3    10075
4    10085
Name: FlightNumber, dtype: int64