#include<bits/stdc++.h>
using namespace std;
string s,k;
int main(){
	getline(cin,k);
	for(int i=0;i<k.size();i++)
	{
		if((i + 1) % 2 == 0 && k[i] >= 'a' && k[i] <= 'z') 
    		k[i] = k[i] - 'a' + 'A';
		if((i + 1) % 2 == 1 && k[i] >= 'A' && k[i] <= 'Z') 
   			k[i] = k[i] - 'A' + 'a';
	}
	cout<<k;
	return 0;
}