#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001



int main(){	
	
	string s;
	cin>>s;
	
	rep(i,s.size()){
		if(islower(s[i]))s[i] = toupper(s[i]);
		else s[i] = tolower(s[i]);
	}
	cout<<s<<endl;
	
	return 0;
	
}