#include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
using namespace std;
typedef long long ll;

int main(){
	string s;
	cin>>s;
	rep(i,s.size()){
  		if (isupper(s[i])) s[i]+=32;
  		else s[i]-=32;
	}
  	rep(i,s.size()) cout << s[i];
  	cout << endl;
}