#include <bits/stdc++.h>

#define REP(i, x, n) for(int i = x; i < (int)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define F first
#define S second
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

int main() {
  // ios_base::sync_with_stdio(false);
  string S;
  cin >> S;
  rep(i, S.size()) {
    if('a' <= S[i] && S[i] <= 'z') S[i] = toupper(S[i]);
    else S[i] = tolower(S[i]);
  }
  cout << S << endl;
  return 0;
}