using namespace std;
int main(){
	char a[505];
	cin.getline(a,505);
	int len=strlen(a);
	for(int i=0;i<=len-1;i++){
		if('A'<=a[i]&&a[i]<='Z'){
			a[i]+=32;
			cout<<a[i]; 
		}
		else if('a'<=a[i]&&a[i]<='z'){
			a[i]-=32;
			cout<<a[i];
		}
		else cout<<a[i];
	}
	return 0;
}