my @compounds=("C3H8O2",
	       "C6H10O5",
	       "C36H62O31",
	       "C5H16N2",
	       "C10H11N5O6P",
	       "C9H11N3O7P",
	       "C3H9N2O2");
print join("\n",
	   sort{($a =~ /C(\d*)/)[0] 
		    <=> 
		($b =~ /C(\d*)/)[0]} 
	   grep { $_ =~ /P/} 
	   @compounds),"\n";