#!/usr/bin/perl

$i=0;
$numpts=16;

while(<>){
	chomp;
	($x, $y)=split;
	if($y ne "??"){
	   push @dat, [ $x, $y ];
	   $i++;
	}
}

for($j=$numpts; $j<$i; $j++){
    $sum=0;
    for($k=$j-$numpts; $k<$j; $k++){
	$sum+=$dat[$k][1];
    }
   print $dat[$j][0], " ", $sum/$numpts, "\n";
}