#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#define REP(i,n) for(int i=0;i<(n);++i)
#define SORT(a) sort((a).begin(),(a).end())
#define PB push_back
using namespace std;
typedef vector<int> VI;

int main(){
  string S;
  cin >> S;
  int l = S.size();
  REP(i,l){
    char c = S[i];
    if(c >= 'a' && c <= 'z'){
      c += 'A' - 'a';
    }else if(c >= 'A' && c <= 'Z'){
      c -= 'A' - 'a';
    }
    S[i] = c;
  }
  cout << S << endl;
}