inheritance

Code:
#include <iostream>
#include <cstdarg>
#include <cstdio>
#include <string>
#include <sstream>
#include <exception>
#include "aibe.h"

class DoesNotExistInSet : public std::exception {
    public:
        DoesNotExistInSet(std::string helpText = "Niekas") :
msg(helpText) {}
        ~DoesNotExistInSet() throw() {}
        virtual const char* what() const throw() {
            return msg.c_str();
        }
    protected:
        std::string msg;
};

class AlreadyExistInSet : public DoesNotExitInSet { // 20
    public:
        AlreadyExistInSet(std::string helpText = "Niekas") :
DoesNotExistInSet(helpText) {} // 22
        ~AlreadyExistInSet() throw() {}
};

aibe.cpp:20: error: expected class-name before =91{' token
aibe.cpp: In constructor
=91AlreadyExistInSet::AlreadyExistInSet(std::string)':
aibe.cpp:22: error: type =91class DoesNotExistInSet' is not a direct
base of =91AlreadyExistInSet'

Started to learn more about C++ and wanted to create some specific
exception and run into problems.
Any ideas how to fix and why I am getting those errors?