#include<iostream>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<string>
#include<math.h>

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<(n);i++)
#define ALL(i) (i).begin(),(i).end()
#define rALL(i) (i).rbegin(),(i).rend()
#define debug(x) cout<<#x<<": "<<x<<endl
#define pi M_PI

typedef long long ll;
typedef unsigned long long ull;

using namespace std;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
/*-------- code --------*/
    string s;
    cin >> s;
    FOR(i,0,s.length()){
        if('a' <= s[i] && s[i] <= 'z'){
            s[i] -= 32;
        } else if('A' <= s[i] && s[i] <= 'Z'){
            s[i] += 32;
        }
    }
    cout << s << endl;
}