高手帮忙

data temp;
   input x y@@;
   if x>50 then class=1;
   else class=2;
cards;
50 34 12 34 45 576 1 34 34;
proc print;
run;

这是在sas9.1.3下的运行上面的结果

NOTE: The data set WORK.TEMP has 0 observations and 3 variables.
NOTE: DATA statement used (Total process time):
      real time           0.01 seconds
      cpu time            0.00 seconds

223  50 34 12 34 45 576 1 34 34;
     --
     180

ERROR 180-322: Statement is not valid or it is used out of proper order.

224  proc print;
225  run;

这是什么意思啊????

在线求解！！！！！！