#include<iostream>
#include<string>
using namespace std;

int main(){
	string in;
	cin >> in;
	
	for(int i = 0; i < in.length(); i++){
		if(in[i] <= 90) cout << (char)(in[i] + 32);
		else cout << (char)(in[i] - 32);
	}
	cout << endl;
}