<?php
$inCount = 10;
$total = 0;
$inSum = 0;
$nonNum = $inCount;

$stdin = trim(fgets(STDIN));
$inNumList = explode(' ', $stdin);
foreach ($inNumList as $key => $inNum) {
    $total += $key + 1;
    $inSum += $inNum;
}
$total += $inCount;

echo ($total-$inSum)."\n";