public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  String a = sc . next ( ) ;
  int [ ] stacks = new int [ a . length ( ) ] ;
  int kaisu = 0 ;
  int pointer = 0 ;
  for ( int i = 0 ;
  i < a . length ( ) ;
  i ++ ) {
    if ( a . charAt ( i ) == 'S' ) {
      stacks [ pointer ] = 1 ;
      pointer ++ ;
    }
    else if ( a . charAt ( i ) == 'T' ) {
      stacks [ pointer ] = 2 ;
      pointer ++ ;
    }
    if ( pointer >= 2 ) {
      if ( stacks [ pointer - 2 ] == 1 && stacks [ pointer - 1 ] == 2 ) {
        stacks [ pointer - 2 ] = 0 ;
        stacks [ pointer - 1 ] = 0 ;
        pointer -= 2 ;
        kaisu ++ ;
      }
    }
  }
  System . out . println ( ( a . length ( ) - kaisu * 2 ) ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; String a = sc . next ( ) ; int [ ] stacks = new int [ a . length ( ) ] ; int kaisu = 0 ; int pointer = 0 ; for ( int i = 0 ; i < a . length ( ) ; i ++ ) { if ( a . charAt ( i ) == ' S ' ) { stacks [ pointer ] = 1 ; pointer ++ ; } else if ( a . charAt ( i ) == ' T ' ) { stacks [ pointer ] = 2 ; pointer ++ ; } if ( pointer >= 2 ) { if ( stacks [ pointer - 2 ] == 1 && stacks [ pointer - 1 ] == 2 ) { stacks [ pointer - 2 ] = 0 ; stacks [ pointer - 1 ] = 0 ; pointer -= 2 ; kaisu ++ ; } } } System . out . println ( ( a . length ( ) - kaisu * 2 ) ) ; }
(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: (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (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))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (update_expression (identifier)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (update_expression (identifier)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)) right: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal)))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))) (expression_statement (update_expression (identifier))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))))))))