public static void main ( String [ ] args ) {
  Scanner s = new Scanner ( System . in ) ;
  final int N = s . nextInt ( ) ;
  final int K = s . nextInt ( ) ;
  s . nextLine ( ) ;
  char [ ] box = s . nextLine ( ) . toCharArray ( ) ;
  int G = 0 ;
  for ( int i = 0 ;
  i < box . length ;
  i ++ ) {
    if ( box [ i ] == 'G' ) {
      G = i ;
      break ;
    }
  }
  boolean found = false ;
  int g = G ;
  while ( g >= 0 ) {
    if ( box [ g ] == 'T' ) {
      found = true ;
      break ;
    }
    if ( box [ g ] == '#' ) {
      break ;
    }
    g -= K ;
  }
  g = G ;
  while ( g < N && ! found ) {
    if ( box [ g ] == 'T' ) {
      found = true ;
      break ;
    }
    if ( box [ g ] == '#' ) {
      break ;
    }
    g += K ;
  }
  if ( found ) {
    System . out . println ( "YES" ) ;
  }
  else {
    System . out . println ( "NO" ) ;
  }
}

public static void main ( String [ ] args ) { Scanner s = new Scanner ( System . in ) ; final int N = s . nextInt ( ) ; final int K = s . nextInt ( ) ; s . nextLine ( ) ; char [ ] box = s . nextLine ( ) . toCharArray ( ) ; int G = 0 ; for ( int i = 0 ; i < box . length ; i ++ ) { if ( box [ i ] == ' G ' ) { G = i ; break ; } } boolean found = false ; int g = G ; while ( g >= 0 ) { if ( box [ g ] == ' T ' ) { found = true ; break ; } if ( box [ g ] == ' # ' ) { break ; } g -= K ; } g = G ; while ( g < N && ! found ) { if ( box [ g ] == ' T ' ) { found = true ; break ; } if ( box [ g ] == ' # ' ) { break ; } g += K ; } if ( found ) { System . out . println ( " YES " ) ; } else { System . out . println ( " NO " ) ; } }
(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 (modifiers) type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration (modifiers) type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (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: (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))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (field_access object: (identifier) field: (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: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))) (break_statement))))) (local_variable_declaration type: (boolean_type) declarator: (variable_declarator name: (identifier) value: (false))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (true))) (break_statement))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (break_statement))) (expression_statement (assignment_expression left: (identifier) right: (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (unary_expression operand: (identifier)))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (true))) (break_statement))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (block (break_statement))) (expression_statement (assignment_expression left: (identifier) right: (identifier))))) (if_statement condition: (parenthesized_expression (identifier)) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))))))