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

int main(){
    string S;
    cin>>S;
    int n=S.length();
    int i;
    for (i=0;i<=n;i++){
        if(S[i]==0){
            continue;
        }
        if(S[i]<94){
            S[i]+=32;
        }else if(S[i]>94){
            S[i]-=32;
        }
    }

    cout<<S<<endl;
}