#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
using vll=vector<ll>;
using pll=pair<ll,ll>;

using mint=modint;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

    string S;
    cin>>S;
    for(auto& s:S){
        if('a'<=s&&s<='z')s=s-'a'+'A';
        else s=s-'A'+'a';
    }
    cout<<S<<endl;
}