complex math complex mathematical complex mathematical problems complex matrices complex matrix complex matter complex matters complex mechanical complex mechanism complex mechanisms complex media complex medical complex medium complex mental complex metal complex method complex methods complex mission complex mix complex mixture complex mixtures complex model complex models complex molecular complex molecule complex molecules complex movement complex movements complex multiplication complex musical complex named complex natural complex nature complex needs complex negotiations complex network complex networks complex new complex number complex numbers complex object complex objects complex of buildings complex offers complex one complex ones complex opens complex operation complex operations complex organ complex organic complex organic molecules complex organism complex organisms complex organization complex organizations complex oxide complex part complex partial complex parts complex password complex passwords complex pattern complex patterns complex person complex personality complex phase complex phenomena complex phenomenon complex physical complex picture complex piece complex pieces complex place complex plane complex planning complex policy complex political complex problem complex problems complex procedure complex procedures complex process complex process involving complex process that requires complex processes complex processing complex product complex production complex products complex program complex programming complex programs complex project complex projective complex projects complex protein complex proteins complex public