static String findString ( int n , int k ) {
  String res = "" ;
  for ( int i = 0 ;
  i < k ;
  i ++ ) res = res + ( char ) ( 'a' + i ) ;
  int count = 0 ;
  for ( int i = 0 ;
  i < n - k ;
  i ++ ) {
    res = res + ( char ) ( 'a' + count ) ;
    count ++ ;
    if ( count == k ) count = 0 ;
  }
  return res ;
}

static String findString ( int n , int k ) { String res = " " ; for ( int i = 0 ; i < k ; i ++ ) res = res + ( char ) ( ' a ' + i ) ; int count = 0 ; for ( int i = 0 ; i < n - k ; i ++ ) { res = res + ( char ) ( ' a ' + count ) ; count ++ ; if ( count == k ) count = 0 ; } return res ; }
(method_declaration (modifiers) type: (type_identifier) 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: (type_identifier) declarator: (variable_declarator name: (identifier) value: (string_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: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (cast_expression type: (integral_type) value: (parenthesized_expression (binary_expression left: (character_literal) right: (identifier)))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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: (binary_expression left: (identifier) right: (identifier))) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (cast_expression type: (integral_type) value: (parenthesized_expression (binary_expression left: (character_literal) right: (identifier))))))) (expression_statement (update_expression (identifier))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))))) (return_statement (identifier))))