#include<iostream>
#include<ctype.h>
#include<string>

using namespace std;

int main(){

    string C;
    cin >> C;

    string S;
    for(char x : C){
	S += ( islower(x) == 0 ? tolower(x) : toupper(x) );
    }
    cout << S << endl;
    return 0;
}