#include<bits/stdc++.h>
using namespace std;

const long long INF = 1LL << 60;
#define MOD 1000000007;

typedef long long ll;

#define writeln(n) cout<<n<<endl;

typedef pair<int, int> P;

typedef pair<string, int> Psi;


int main() {

	string s;
	cin>>s;

	int cnt=0;
	string ans ="";
	for(int i=s.size()-1; i>=0; i--){
		cnt++;

		if(cnt ==4){
			ans +=",";
			cnt=1;
		}
		ans += string(1,s[i]);


	}
	reverse(ans.begin(),ans.end());

	writeln(ans);
}