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