0) return gcd($b, $a % $b); else return $a; } echo "test\n"; const N = 1000; $A = array(); for ($i = 0; $i < N; $i++) { $A[$i] = $i; } $ans = 0; foreach ($A as $i) { foreach ($A as $j) { $ans += gcd($i, $j); } } echo $ans;