#include<bits/stdc++.h>
using namespace std;

string a;
int main(){
	cin>>a;
	for(int i=0;i<a.size();i++){
		if(i==0) if(!(a[i]>='A'&&a[i]<='Z')) a[i]=(char)a[i]+32;
		else if(!(a[i]>='a'&&a[i]<='z')) a[i]=(char)a[i]-32;
	}
	cout<<a<<endl;
	return 0;
}