#include <iostream>
#include <cstdio>

using namespace std;

int main(void){
    string s; cin>>s;
    for(int i=0;i<s.size();i++){
        if(s[i]>='A'&&s[i]<='Z') s[i]+=32;
        else s[i]-=32;
    }
    cout<<s<<endl;
}