#include <bits/stdc++.h>   using namespace std;   int main() {     char a[1000];     cin >> a;     int n = strlen(a), i, up = 1;     for (i = 1; i < n; i++)       if (a[i] >=  a  && a[i] <=  z ) up = 0;     if (up) {       for (i = 1; i < n; i++) a[i] = a[i] +  a  -  A ;       if (a[0] >=  A  && a[0] <=  Z )         a[0] = a[0] +  a  -  A ;       else         a[0] = a[0] +  A  -  a ;     }     cout << a;   }   