>>878 Perl
# 簡略化
use bigint;

$am = $b0 = 1;
$a0 = $bm = 0;

for($m = $N = $ARGV[0]; $m ;$m /= 2) {
$a0b0 = $a0 * $b0;
$b0b0 = $b0 * $b0;
($a0, $am) = ($a0b0 + $am * $b0 + $a0 * $bm, $a0b0 + $am * $bm) if $m % 2;
($b0, $bm) = ($b0b0 + 2 * $b0 * $bm, $b0b0 + $bm * $bm)
}
print "F_$N = $a0\n";