Perl
-
I tried a little harder this time. It's a really <strike>simple</strike> complex strategy, but I've set up the framework for expansion.

Edit: It has been changed back to the original to improve performance..

    $_=<>;
    INPUT:{

    tr/ /,/;
    @in = eval;
    @rbids = "";
    for(1..$#in){
     $rbids[$in[$_]]++
    }
    
    LOWBID: for($pnt=1;$pnt<$#in+1;$pnt++){
     if($rbids[$pnt]==0){$lows[$pnt]++;last LOWBID}
    }
    
    $_=<>;
    if($_ ne"\n"){redo INPUT}
    }
    
    $max=0;
    $maxloc=3;
    for(1..100){
     if($lows[$_]>$max){$maxloc=$_;$max=$lows[$_]}
    }
    print$maxloc
This program takes input one line at a time, followed by two newlines:

    perl PhiNotPi2.plx
    1 2 3 3 2
    2 1 3 1 3
    2 1 1 1 3
    [empty line]