comefrom: <awangdev>509. Fibonacci Number_3.java
code: public int fibonacci(int n) {
          if (n <= 1) {
              return 0;
          } 
          if (n == 2) {
              return 1;
          }
          return fibonacci(n - 1) + fibonacci(n - 2);
      }
masked: public int sample_funcname ( int n ) {
    if ( n <= 1 ) {
      return 0 ;
    }
    if ( n == 2 ) {
      return 1 ;
    }
    return fibonacci ( n - 1 ) + fibonacci ( n - 2 ) ;
  }
  