Ubiquitous Religions

/**
 *    author: Akvicor
 *    created: 2019-06-19 15-56-44
**/

#include <cstdio>
#include <cstring>
#include <iomanip>
#include <ctime>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <stack>
#include <bitset>
#include <complex>
#include <cstdlib>
#include <cmath>
#include <set>
#include <list>
#include <deque>
#include <map>
#include <queue>

using namespace std;

#ifdef DEBUG
string to_string(string s) {
	return '"' + s + '"';
}

string to_string(const char* s) {
	return to_string((string) s);
}

string to_string(bool b) {
return (b ? "true" : "false");
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
	return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A>
string to_string(A v) {
	bool first = true;
	string res = "{";
	for (const auto &x : v) {
		if (!first) {
			res += ", ";
		}
		first = false;
		res += to_string(x);
	}
	res += "}";
	return res;
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	cerr << " " << to_string(H);
	debug_out(T...);
}
#endif

#ifdef DEBUG
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 17
#endif

#ifdef DEBUG
#define FAST_IO 17
#define cout cout << "-->"
#else
#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define endl '\n'
#endif

#define LL long long
#define ULL unsigned long long
#define rep(i, n) for(int i = 0; i < (n); ++i)
#define reep(i, n) for(int i = 0; i <= (n); ++i)
#define lop(i, a, n) for(int i = a; i < (n); ++i)
#define loop(i, a, n) for(int i = a; i <= (n); ++i)
#define ALL(v) (v).begin(), (v).end()
#define PB push_back
#define VI vector<int>
#define PII pair<int,int>
#define FI first
#define SE second
#define SZ(x) ((int)(x).size())

const double EPS = 1e-6;
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
const LL LINF = 0x7f7f7f7f7f7f7f7f;
const int MAXN = (int)1e6 + 10;
const int MOD = (int)1e9 + 7;

class UnionFind{
	private:
		int * parents;
		int * sz;
		int count;
	public:
		UnionFind(int n){
			this->count = n;
			parents = new int[n];
			sz = new int[n];
			for(int i = 0; i < n; ++i){
				parents[i] = i;
				sz[i] = 1;
			}
		}
		~UnionFind(){
			delete [] parents;
			delete [] sz;
		}

		int find(int p){
			while(p != parents[p]) p = parents[p];	
			return p;
		}

		void unionElements(int p, int q){
			int pRoot = find(p);
			int qRoot = find(q);
			
			if(pRoot == qRoot) return;

			if(sz[pRoot] < sz[qRoot]){
				parents[pRoot] = qRoot;
				sz[qRoot] += sz[pRoot];
			}else{
				parents[qRoot] = pRoot;
				sz[pRoot] += sz[qRoot];
			}
		}

		int ans(){
			int cnt = 0;
			for(int i = 0; i < this->count; ++i){
				if(parents[i] == i) ++cnt;
			}
			return cnt;
		}
};

int n, m, i, j, cnt = 0;

int main(){
	FAST_IO;

	while(cin >> n >> m && (n || m)){
		++cnt;
		//if(n==0 && m==0) break;
		UnionFind uf = UnionFind(n);
		while(m--){
			cin >> i >> j;
			uf.unionElements(i-1, j-1);
		}
		cout << "Case " << cnt << ": " << uf.ans() << endl;
	}

	return 0;
}