#include<iostream>
#include<cctype>
#include<string>
#include<algorithm>

int main(){
    std::string intention;
    std::cin >> intention;
    std::transform(intention.begin(),intention.end(),intention.begin(),
        [](char c)->char{
            if(std::isupper(c)){
                return std::tolower(c);
            }
            else if(std::islower(c)){
                return std::toupper(c);
            }
        });
    std::cout<<intention<<std::endl;
    return 0;
}