#include <cstdio>
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <functional>
#include <queue>
#include <stack>
#include <cmath>
#include <iomanip>
 
using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define CLR(a) memset((a), 0 ,sizeof(a))
#define MCLR(a) memset((a), -1 ,sizeof(a))
#define SZ(a) (sizeof(a))
#define FILL(a,v) fill((int*)a,(int*)(a+(SZ(a)/SZ(*(a)))),v)

bool cheak(int x,int y,int xMax,int yMax)
{return x >= 0 && y >= 0 && xMax > x && yMax > y;}
const int dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
const int INF = 2147483647;
typedef pair<int,int> P;
typedef long long ll;
typedef unsigned long long ull;


int main()
{
	string s;
	string ans;
	cin >> s;

	REP(i,s.size())
	{
		if(s[i] >= 'a' && s[i] <= 'z')
		ans += s[i]-'a'+'A';
		else
		if(s[i] >= 'A' && s[i] <= 'Z')
		ans += s[i]-'A'+'a';
	}

	cout << ans << endl;


	return 0;
}