p should be prime
$ p = 113 ; $ x = STonelli ( $ n , $ p ) ; if ( $ x == -1 ) print ( " Modular ▁ square ▁ root ▁ is ▁ not ▁ exist STRNEWLINE " ) ; else print ( " Modular ▁ square ▁ root ▁ of ▁ " . " $ n ▁ and ▁ $ p ▁ is ▁ $ x STRNEWLINE " ) ; ? >