public static void main ( String [ ] args ) {
  Scanner input = new Scanner ( System . in ) ;
  int n = input . nextInt ( ) , t = input . nextInt ( ) , k = input . nextInt ( ) , d = input . nextInt ( ) ;
  int x = t * ( n / k ) ;
  if ( n % k != 0 ) x += t ;
  System . out . println ( t + d >= x ? "NO" : "YES" ) ;
  ;
}

public static void main ( String [ ] args ) { Scanner input = new Scanner ( System . in ) ; int n = input . nextInt ( ) , t = input . nextInt ( ) , k = input . nextInt ( ) , d = input . nextInt ( ) ; int x = t * ( n / k ) ; if ( n % k != 0 ) x += t ; System . out . println ( t + d >= x ? " NO " : " YES " ) ; ; }
(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))) 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: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (identifier) right: (identifier)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal))) consequence: (expression_statement (assignment_expression left: (identifier) right: (identifier)))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (ternary_expression condition: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier)) consequence: (string_literal) alternative: (string_literal)))))))