#include<iostream>
#include<string>

using namespace std;

int main(void)
{
    const int big_small='a'-'A';
    
    string s;
    cin>>s;
    
    for(int i=0;i<s.size();i++)
    {
        if(s[i]>='a')
        {
            char tmp=s[i]-big_small;
            cout<<tmp;
        }
        else
        {
            char tmp=s[i]+big_small;
            cout<<tmp;
        }
    }
    cout<<endl;
    
    
}