#!blah
#untested!
#use strict, etc.
my $bs; #your big string--how you get the data in there is up 2 u
my ($lms, $lmn); #last matched string,num
my $max = 0;# biggest
while ($bs !~ m/\G\z/ms){
  if ($bs =~ m/\G([[:upper:]]+)\s*/g){#[:alpha:],whatever
     $lms = $1;
  }elsif ($bs =~ m/\G(\d+)\s*/g){#[:alpha:],whatever
     #up to the closing brace before else, 
     #$lms corresponds to the text before this number
     $lmn = $1;
     if ($lmn > $max){
       #at this point, $lms is the text before the biggest int so far
       $max = $lmn;
     }
  }else{
     die "unexpected data near character".pos();
  }
}