private static long countWays ( int length , int m ) {
  long [ ] ways = new long [ length + 1 ] ;
  ways [ 0 ] = 1 ;
  for ( int n = 1 ;
  n <= length ;
  n ++ ) {
    ways [ n ] += ways [ n - 1 ] ;
    if ( n >= m ) ways [ n ] += ways [ n - m ] ;
  }
  return ways [ length ] - 1 ;
}

private static long countWays ( int length , int m ) { long [ ] ways = new long [ length + 1 ] ; ways [ 0 ] = 1 ; for ( int n = 1 ; n <= length ; n ++ ) { ways [ n ] += ways [ n - 1 ] ; if ( n >= m ) ways [ n ] += ways [ n - m ] ; } return ways [ length ] - 1 ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (decimal_integer_literal)) right: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (identifier)))))))) (return_statement (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)))))