#include <cstdio>
#include <cmath>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <map>
#include <set>
#include <array>
#include <queue>
#include <string>
#include <vector>
#include <numeric>
#include <algorithm>
#include <functional>
#define MOD 1000000007
#define INF 11234567890
#define in std::cin
#define out std::cout
#define rep(i,N) for(LL i=0;i<N;++i)
typedef long long int LL;
typedef std::pair<int, int> P;

std::string S;
char str_min[] = { 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' };
char str_max[] = { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z' };

int main()
{
	in >> S;
	
	rep(i, S.length())
	{
		if (S[i] - 'A' < 26)
		{
			S[i] = str_min[S[i] - 'A'];
		}
		else
		{
			S[i] = str_max[S[i] - 'a'];
		}
	}

	out << S << std::endl;
	return 0;
}