/*#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<map>
#include<cstdio>
#include<stack>
#include<queue>
#include<fstream>
#include<cstdio>
#include<deque>
#include<iomanip>
#include <random>

using namespace std;
#define ok1 printf("ok1\n");
#define ok2 printf("ok2\n");
#define M 1000000000000000000LL
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,s,n) for(int i=(s);i<(n);i++)
#define repr(i,n) for(int i=n-1;i>=0;i--)
#define REPR(i,s,n) for(int i=(s);i>=(n);(i)--)
#define all(a) (a).begin(),(a).end()
#define reall(a) (a).rbegin(),(a).rend()
#define pb push_back
#define pf push_front
#define MIN(a,b) a=min((a),(b))
#define MAX(a,b) a=max((a),(b))
#define SIZE(v) (int)v.size()
const double pi = acos(-1.0);

typedef vector<int> vi;
typedef vector<string> vs;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef deque<ll> dll;
#define mod 1e9 + 7;

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	cout.setf(ios::fixed);
	cout.precision(20);

	vs v;
	string s1, s2;
	vs cs1, cs2;
	while (true) {
		cin >> s1;
		if (s1 == ".") break;
		cin >> s2;
		ll sum = 0;
		if (s1 == s2) v.pb("IDENTICAL");
		else {
			rep(i, s1.size()) {
				rep(j, s1.size()) {
					if (i != j && s1[i] == '"' && s1[j] == '"') {
						cs1.pb(s1.substr(i + 1, j - 1));
						s1[i] = '0'; s1[j] = '0';
					}

				}
			}
			rep(i, s2.size()) {
				rep(j, s2.size()) {
					if (i != j && s2[i] == '"' && s2[j] == '"') {
						cs2.pb(s2.substr(i + 1, j - 1));
						s2[i] = '0'; s2[j] = '0';
					}

				}
			}
			rep(i, cs1.size()) {
				cout << cs1[i] << " " << cs2[i] << endl;
				if (cs1[i] != cs2[i]) sum++;
				if (sum == 2) break;
			}
			if (sum == 1) v.pb("CLOSE");
			else v.pb("DIFFERENT");
		}
	}
	rep(i, v.size()) cout << v[i] << endl;
	return 0;
}*/
#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<map>
#include<cstdio>
#include<stack>
#include<queue>
#include<fstream>
#include<cstdio>
#include<deque>
#include<iomanip>

using namespace std;
#define ok1 printf("ok1\n");
#define ok2 printf("ok2\n");
#define M 1000000000000000000LL
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,s,n) for(int i=(s);i<(n);i++)
#define repr(i,n) for(int i=n-1;i>=0;i--)
#define REPR(i,s,n) for(int i=(s);i>=(n);(i)--)
#define all(a) (a).begin(),(a).end()
#define reall(a) (a).rbegin(),(a).rend()
#define pb push_back
#define pf push_front
#define MIN(a,b) a=min((a),(b))
#define MAX(a,b) a=max((a),(b))
#define SIZE(v) (int)v.size()
const double pi = acos(-1.0);

typedef vector<int> vi;
typedef vector<string> vs;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef deque<ll> dll;
#define mod 1e9 + 7;

bool check(string s1, string s2) {
	//cout << s1 << " " << s2 << endl;
	ll l = 0, r = 0, cnt = 0;
	while(l < s1.size() || r < s2.size()) {
		if (s1.size() == l || s2.size() == r) return false;
		if (s1[l] != s2[r]) return false;
		if (s1[l] == '"') {
			l++;
			string ss = "";
			while (s1[l] != '"') {
				ss += s1[l];
				l++;
			}
			l++;
			r++;
			string ss2 = "";
			while (s2[r] != '"') {
				ss2 += s2[r];
				r++;
			}
			r++;
			if (ss != ss2) cnt++;
		}
		else {
			l++; r++;
		}
	}
	if (l == s1.size() && r == s2.size() && cnt <= 1) return true;
	else return false;
}
int main()
{
	ios_base::sync_with_stdio(false);

	string s1,s2;
	while (cin >> s1) {
		if (s1 == ".") break;
		cin >> s2;
		if (s1 == s2) cout << "IDENTICAL" << endl;
		else {
			if (check(s1, s2)) {
				cout << "CLOSE" << endl;
			}
			else cout << "DIFFERENT" << endl;

		}
	}
	return 0;
}



Measured memory_bytes: 3140