View Compilation Error

0_0_5509583_14745\Main.java:5: cannot find symbol
symbol  : variable n
location: class Main
     return n*(n+1)/2;         
            ^
0_0_5509583_14745\Main.java:5: cannot find symbol
symbol  : variable n
location: class Main
     return n*(n+1)/2;         
               ^
0_0_5509583_14745\Main.java:11: cannot find symbol
symbol  : class Scanner
location: class Main
      Scanner cin = new Scanner(System.in);
      ^
0_0_5509583_14745\Main.java:11: cannot find symbol
symbol  : class Scanner
location: class Main
      Scanner cin = new Scanner(System.in);
                        ^
0_0_5509583_14745\Main.java:14: getResult(int) in Main cannot be applied to ()
       result = getResult();   
                ^
5 errors