template<typename T, typename Iterator>
Iterator FindImpl(const T& v, Iterator first,
Iterator last, std::bidirectional_iterator_tag) {
while (first != last) {
if (*first == v) return first;
first++;
}
return last;
}


template<typename T, typename Iterator>
Iterator FindImpl(const T& v, Iterator first,
Iterator last, std::random_access_iterator_tag) {
Iterator end = last;
while (first != last) {
Iterator middle = first + ((last - first) / 2);
if (*middle < v) {
first = middle + 1;
} else {
last = middle;
}
}
if (*last == v) return last;
return end;
}

template<typename T, typename Iterator>
Iterator Find(const T& value, Iterator first, Iterator last) {
typedef typename std::iterator_traits<Iterator>::iterator_category category;
return FindImpl(value, first, last, category());
}