#include<iostream>
#include<stdio.h>

using namespace std;

int main(){

    string str;
    cin>> str;

    for(int i=0; i<str.size(); i++){
        if(str[i]<91){
            str[i] = str[i]+32;
        }else{
            str[i] = str[i]-32;
        }
    }

    cout<< str<< endl;
    return 0;
}