#include <bits/stdc++.h>

[[nodiscard]] static inline constexpr std::string solve(std::string&& S) noexcept
{
	for (auto& s : S)
	{
		if (std::islower(s)) s = toupper(s);
		else s = tolower(s);
	}

	return S;
}

int main()
{
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	
	std::string S;
	S.reserve(100);
	std::cin >> S;

	std::cout << solve(std::move(S)) << '\n';
	return 0;
}