namespace std {
template<class Iterator> struct iterator_traits;
template<class T> struct iterator_traits<T*>;
template<class Category, class T, class Distance = ptrdiff_t,
class Pointer = T*, class Reference = T&> struct iterator;
struct input_iterator_tag { };
struct output_iterator_tag { };
struct forward_iterator_tag: public input_iterator_tag { };
struct bidirectional_iterator_tag: public forward_iterator_tag { };
struct random_access_iterator_tag: public bidirectional_iterator_tag { };
template <class InputIterator, class Distance>
void advance(InputIterator& i, Distance n);
template <class InputIterator>
typename iterator_traits<InputIterator>::difference_type
distance(InputIterator first, InputIterator last);
template <class ForwardIterator>
ForwardIterator next(ForwardIterator x,
typename std::iterator_traits<ForwardIterator>::difference_type n = 1);
template <class BidirectionalIterator>
BidirectionalIterator prev(BidirectionalIterator x,
typename std::iterator_traits<BidirectionalIterator>::difference_type n = 1);
template <class Iterator> class reverse_iterator;
template <class Iterator1, class Iterator2>
bool operator==(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator<(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator!=(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator>(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator>=(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator<=(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
auto operator-(
const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y) ->decltype(y.base() - x.base());
template <class Iterator>
reverse_iterator<Iterator>
operator+(
typename reverse_iterator<Iterator>::difference_type n,
const reverse_iterator<Iterator>& x);
template <class Iterator>
reverse_iterator<Iterator> make_reverse_iterator(Iterator i);
template <class Container> class back_insert_iterator;
template <class Container>
back_insert_iterator<Container> back_inserter(Container& x);
template <class Container> class front_insert_iterator;
template <class Container>
front_insert_iterator<Container> front_inserter(Container& x);
template <class Container> class insert_iterator;
template <class Container>
insert_iterator<Container> inserter(Container& x, typename Container::iterator i);
template <class Iterator> class move_iterator;
template <class Iterator1, class Iterator2>
bool operator==(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator!=(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator<(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator<=(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator>(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
bool operator>=(
const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
auto operator-(
const move_iterator<Iterator1>& x,
const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
template <class Iterator>
move_iterator<Iterator> operator+(
typename move_iterator<Iterator>::difference_type n, const move_iterator<Iterator>& x);
template <class Iterator>
move_iterator<Iterator> make_move_iterator(Iterator i);
template <class T, class charT = char, class traits = char_traits<charT>,
class Distance = ptrdiff_t>
class istream_iterator;
template <class T, class charT, class traits, class Distance>
bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
const istream_iterator<T,charT,traits,Distance>& y);
template <class T, class charT, class traits, class Distance>
bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
const istream_iterator<T,charT,traits,Distance>& y);
template <class T, class charT = char, class traits = char_traits<charT> >
class ostream_iterator;
template<class charT, class traits = char_traits<charT> >
class istreambuf_iterator;
template <class charT, class traits>
bool operator==(const istreambuf_iterator<charT,traits>& a,
const istreambuf_iterator<charT,traits>& b);
template <class charT, class traits>
bool operator!=(const istreambuf_iterator<charT,traits>& a,
const istreambuf_iterator<charT,traits>& b);
template <class charT, class traits = char_traits<charT> >
class ostreambuf_iterator;
template <class C> auto begin(C& c) -> decltype(c.begin());
template <class C> auto begin(const C& c) -> decltype(c.begin());
template <class C> auto end(C& c) -> decltype(c.end());
template <class C> auto end(const C& c) -> decltype(c.end());
template <class T, size_t N> constexpr T* begin(T (&array)[N]) noexcept;
template <class T, size_t N> constexpr T* end(T (&array)[N]) noexcept;
template <class C> constexpr auto cbegin(const C& c) noexcept(noexcept(std::begin(c)))
-> decltype(std::begin(c));
template <class C> constexpr auto cend(const C& c) noexcept(noexcept(std::end(c)))
-> decltype(std::end(c));
template <class C> auto rbegin(C& c) -> decltype(c.rbegin());
template <class C> auto rbegin(const C& c) -> decltype(c.rbegin());
template <class C> auto rend(C& c) -> decltype(c.rend());
template <class C> auto rend(const C& c) -> decltype(c.rend());
template <class T, size_t N> reverse_iterator<T*> rbegin(T (&array)[N]);
template <class T, size_t N> reverse_iterator<T*> rend(T (&array)[N]);
template <class E> reverse_iterator<const E*> rbegin(initializer_list<E> il);
template <class E> reverse_iterator<const E*> rend(initializer_list<E> il);
template <class C> auto crbegin(const C& c) -> decltype(std::rbegin(c));
template <class C> auto crend(const C& c) -> decltype(std::rend(c));
}