#include<iostream>
#include<cstring>
using namespace std;
char a[114514];
const int CAPS=32;
int main()
{
    cin.getline(a,114514);
    for(int i=0;i<strlen(a);i++)
    {
        if('A'<=a[i]&&a[i]<='Z')a[i]+=CAPS;
        else if('a'<=a[i]&&a[i]<='z')a[i]-=CAPS;
    }
    cout<<a;
    return 0;
}