<?php

$count = trim(fgets(STDIN));
$numStr = trim(fgets(STDIN));

$nums = str_split($numStr);

rsort($nums);
$totala = 0;
$totalb = 0;

//$totala = $totala + $nums[0];
if (array_sum($nums)%2 === 0) {
    
    foreach ($nums as $value) {
        if($totala > $totalb) {
            $totalb = $totalb + $value;
        } else {
            $totala = $totala + $value;
        }
    }
    
    if($totala === $totalb) {
    echo "Possible" . "\n";
    //echo "A:" . $totala . "\n";
    //echo "B:" . $totalb;
}
} else {
    echo "Impossible";
}

?>