#include <stdio.h>
#include <iostream>
#include <math.h>
#include <iomanip>
using namespace std;
#define LL Long Long
const int N=1e5+10;
const int INF=0x3f3f3f3f;
int main()
{

    char a;
    cin>>a;
    if(a>=65&&a<=90){
            a+=32;
        }else if(a>=97&&a<=122){
            a-=32;
        }
    cout<<a;
    

}