#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <math.h>
#include <vector>
#include <queue>
#include <algorithm>
#include <sstream>
#include <string>
#include <map>

using namespace std;

#define FOR(I,N) for(int I = 0; I < (int)(N); I++)
#define FIN(V) cout<<V<<endl
#define pb push_back
#define INF (1 << 30)

typedef pair<int, int> P;

string sValueOf(int v){stringstream ss;ss<<v;return ss.str();}
int parseInt(string v){int i;stringstream ss(v);ss>>i;return i;}
void fast_io() {cin.tie(0); ios::sync_with_stdio(false);}

char change(char c){
	if('A'<=c&&c<='Z'){
		c+=('a'-'A');
	}else{
		c-=('a'-'A');
	}
	return c;
}

int main(){
	int i,j;
	string in;
	cin>>in;
	FOR(i,in.length()){
		in[i] = change(in[i]);
	}
	cout<<in<<endl;
	return 0;
}