public static void main ( String [ ] args ) {
  final Scanner sc = new Scanner ( System . in ) ;
  long r = sc . nextLong ( ) ;
  long b = sc . nextLong ( ) ;
  long x = sc . nextLong ( ) ;
  long y = sc . nextLong ( ) ;
  long Tmax = r + b + 1000L ;
  long Tmin = 0L ;
  long T = 0 ;
  while ( Tmax - Tmin > 1 ) {
    T = Tmin + ( Tmax - Tmin ) / 2 ;
    if ( r >= T && b >= T && ( r - T ) / ( x - 1 ) + ( b - T ) / ( y - 1 ) >= T ) {
      Tmin = T ;
    }
    else {
      Tmax = T ;
    }
  }
  long ans = Tmin ;
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { final Scanner sc = new Scanner ( System . in ) ; long r = sc . nextLong ( ) ; long b = sc . nextLong ( ) ; long x = sc . nextLong ( ) ; long y = sc . nextLong ( ) ; long Tmax = r + b + 1000L ; long Tmin = 0L ; long T = 0 ; while ( Tmax - Tmin > 1 ) { T = Tmin + ( Tmax - Tmin ) / 2 ; if ( r >= T && b >= T && ( r - T ) / ( x - 1 ) + ( b - T ) / ( y - 1 ) >= T ) { Tmin = T ; } else { Tmax = T ; } } long ans = Tmin ; 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 (modifiers) 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)))) (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: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal))) body: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (decimal_integer_literal))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (identifier))) right: (binary_expression left: (binary_expression left: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))))) right: (identifier)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (identifier)))) alternative: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))