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

#define REP(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define REMOVE(Itr,n) (Itr).erase(remove((Itr).begin(),(Itr).end(),n),(Itr).end())
#define PB_VEC(Itr1,Itr2) (Itr1).insert((Itr1).end(),(Itr2).begin(),(Itr2).end())
typedef long long ll;

int main(){
    
    string s; cin >> s;
    REP(i,s.size()) {
        if(s[i] >= 'a' && s[i] <= 'z') s[i] = 'A' + (s[i] - 'a');
        else s[i] = 'a' + (s[i] - 'A');
    }
    
    cout << s << endl;
    
    return 0;
}