public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) , k = sc . nextInt ( ) ;
  String s = sc . next ( ) ;
  char [ ] ar = new char [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    ar [ i ] = s . charAt ( i ) ;
  }
  if ( n == k ) {
    if ( n == 1 ) System . out . println ( 0 ) ;
    else {
      System . out . print ( 1 ) ;
      for ( int i = 1 ;
      i < n ;
      i ++ ) System . out . print ( 0 ) ;
    }
  }
  else {
    for ( int i = 0 ;
    i < n && k > 0 ;
    i ++ ) {
      if ( i == 0 ) {
        if ( ar [ i ] != '1' ) {
          k -- ;
          ar [ i ] = '1' ;
        }
      }
      else {
        if ( ar [ i ] != '0' ) {
          k -- ;
          ar [ i ] = '0' ;
        }
      }
    }
    for ( char i : ar ) System . out . print ( i ) ;
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) , k = sc . nextInt ( ) ; String s = sc . next ( ) ; char [ ] ar = new char [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { ar [ i ] = s . charAt ( i ) ; } if ( n == k ) { if ( n == 1 ) System . out . println ( 0 ) ; else { System . out . print ( 1 ) ; for ( int i = 1 ; i < n ; i ++ ) System . out . print ( 0 ) ; } } else { for ( int i = 0 ; i < n && k > 0 ; i ++ ) { if ( i == 0 ) { if ( ar [ i ] != '1' ) { k -- ; ar [ i ] = '1' ; } } else { if ( ar [ i ] != '0' ) { k -- ; ar [ i ] = '0' ; } } } for ( char i : ar ) System . out . print ( i ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (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 (identifier))))) (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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (decimal_integer_literal)))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (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: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (decimal_integer_literal)))))))) alternative: (block (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (expression_statement (update_expression (identifier))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal)))))) alternative: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (expression_statement (update_expression (identifier))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))))))))) (enhanced_for_statement type: (integral_type) name: (identifier) value: (identifier) body: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))))))))