'Data file p1-writ.dat: Names of output files' 1 / (only two-point rays will be stored) 'r .out' 'r i.out' 't .out' / 's0 .out' 's0 i.out' '1' '2' '3' '4' '5' '6' '7' '8' '9' / / '01' / '02' / '03' / '04' / '05' / '06' / '07' / '08' / '09' / '10' / '11' / '12' / '13' / '14' / '15' / '16' / '17' / '18' / '19' / '20' / '21' / '22' / '23' / '24' / '25' / '26' / '27' / '28' / '29' / '30' / '31' / '32' / '33' / '34' / '35' / '36' / '37' / '38' / '39' / '40' /