#include<bits/stdc++.h>
using namespace std;
int main()
{
	char s[81];
	int i;
	gets(s);
	for(i=0;s[i]!='\0';i++){
		if(s[i]>='a'&&s[i]<='z'){
			s[i]=char(int(s[i])-32);
		}else if(s[i]>='A'&&s[i]<='Z'){
			s[i]=char(int(s[i])+32);
		}
	}
	cout<<s<<endl;
	return 0;
}

/**************************************************************
	Problem: 1182
	User: zzz
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/