class RuntimeError(Exception):pass


class VariableNotFoundError(RuntimeError):pass


class VariableAlreadyDefinedError(RuntimeError):pass


class InvalidAssignmentError(RuntimeError):pass


class InvalidFunctionCallError(RuntimeError):pass


class InvalidLifetimeError(RuntimeError):pass


class LifetimeExpiredError(RuntimeError):pass


class StackEmptyError(RuntimeError):pass


class FileSwitchException(RuntimeError):pass


class RuntimeTypeError(RuntimeError):pass