title: the number of vowels in a file
body: <p>Can someone help me with this? Thanks very much. And this is my code:</p>
  
  <pre><code>G = LOAD 'input.txt' AS (line:chararray);
  B = foreach G generate FLATTEN(STRSPLIT(LOWER(line), '(?&lt;=.)(?=.)')) as s:chararray;
  C = foreach B generate FLATTEN(TOBAG(*)) as letter;
  result = filter C by ( letter == 'a' or  letter == 'e' or letter == 'i' or letter == 'o' or letter == 'u' );
  E = GROUP result BY letter;
  F = foreach E generate group, COUNT(result) ;
  DUMP F；
  </code></pre>