filter_complex argument:
[0:v][1:v]overlay=shortest=1:format=yuv420[video];[2:a]apad=whole_dur=13.556[length0],[3:a]apad=whole_dur=18.663[length1],[4:a]apad=whole_dur=21.641[length2],[5:a]apad=whole_dur=34.064[length3],[6:a]apad=whole_dur=28.62[length4],[7:a]apad=whole_dur=30.513[length5],[8:a]apad=whole_dur=22.376[length6],[9:a]apad=whole_dur=68.041[length7],[10:a]apad=whole_dur=21.224[length8],[11:a]apad=whole_dur=27.165[length9],[12:a]apad=whole_dur=25.5[length10],[13:a]atrim=duration=18.605[length11];[length0][length1][length2][length3][length4][length5][length6][length7][length8][length9][length10][length11]concat=n=12:v=0:a=1[audio]

Option 'whole_dur' not found\n[AVFilterGraph @ 0x6b71940] Error initializing filter 'apad' with args 'whole_dur=13.556'\nError initializing complex filters.\nOption not found\n"