public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t -- > 0 ) {
    int n = sc . nextInt ( ) ;
    int c0 = sc . nextInt ( ) ;
    int c1 = sc . nextInt ( ) ;
    int h = sc . nextInt ( ) ;
    char a [ ] = sc . next ( ) . toCharArray ( ) ;
    int cnt0 = 0 , cnt1 = 0 ;
    for ( int i = 0 ;
    i < n ;
    i ++ ) {
      if ( a [ i ] == '0' ) cnt0 ++ ;
    }
    cnt1 = n - cnt0 ;
    int ans = 0 ;
    if ( c0 >= c1 + h ) {
      ans = c1 * cnt1 + ( c1 + h ) * cnt0 ;
    }
    else if ( c1 >= c0 + h ) {
      ans = c0 * cnt0 + ( c0 + h ) * cnt1 ;
    }
    else ans = c0 * cnt0 + c1 * cnt1 ;
    System . out . println ( ans ) ;
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t -- > 0 ) { int n = sc . nextInt ( ) ; int c0 = sc . nextInt ( ) ; int c1 = sc . nextInt ( ) ; int h = sc . nextInt ( ) ; char a [ ] = sc . next ( ) . toCharArray ( ) ; int cnt0 = 0 , cnt1 = 0 ; for ( int i = 0 ; i < n ; i ++ ) { if ( a [ i ] == '0' ) cnt0 ++ ; } cnt1 = n - cnt0 ; int ans = 0 ; if ( c0 >= c1 + h ) { ans = c1 * cnt1 + ( c1 + h ) * cnt0 ; } else if ( c1 >= c0 + h ) { ans = c0 * cnt0 + ( c0 + h ) * cnt1 ; } else ans = c0 * cnt0 + c1 * cnt1 ; System . out . println ( ans ) ; } }
(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)))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) value: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) 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: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (expression_statement (update_expression (identifier)))))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (identifier)))))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (identifier)))))) alternative: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))