#include <initializer_list>
namespace std {
template <class T, class Container = deque<T>> class stack;
template <class T, class Container>
bool operator==(const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
bool operator< (const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
bool operator!=(const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
bool operator> (const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
bool operator>=(const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
bool operator<=(const stack<T, Container>& x, const stack<T, Container>& y);
template <class T, class Container>
void swap(stack<T, Container>& x, stack<T, Container>& y) noexcept(noexcept(x.swap(y)));
}