Java Error: Could not find or load main class -

package src.sheet1.question1;  class onefourtwoone {      public static void main(string[] args) {          assert args.length == 1;          int x = integer.parseint(args[0]);          system.out.print(x);          while(x != 1) {             x = next(x);             system.out.print(" " + x);         };      }      static int next(int x) {          return ((x % 2) == 0) ? (x / 2) : (3*x + 1);      }  } 

when input :java onefourtwoone in terminal, here occurs error: error: not find or load main class onefourtwoone how can run it?

java cannot run class because in package. java expects package name matched path file.

create directory structure looks this:

src   +-sheet1      +-question1         +-onefourtwoone.java 

and compile class onefourtwoone.class. switch parent directory of src, , execute command

java src.sheet1.question1.onefourtwoone