//https://www.e-olymp.com/ru/problems/4371

#pragma GCC optimize ("O3")

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <chrono>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <deque>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <stdarg.h>
#include <utility>

#define MAXN 1000000
#define MOD 10000000000
#define LOCAL

using namespace std;

vector <int> g[100001];
int parent[100001] = {0};
int rankk[100001];


queue <int> q;
int top[100001] = {0};
int used[100001] = {0};
int d[100001] = {0};
int kol = 0;


int make_set(int v) {
    parent[v] = v;
    rankk[v] = 0;
    kol++;
    return 0;
}

int find_set(int v) {
    if(v == parent[v])
        return v;
    return parent[v] = find_set(parent[v]);
}

int union_set(int a, int b) {
    a = find_set(a);
    b = find_set(b);
    if(a == b)
        return 0;
    kol--;
    if(rankk[a] < rankk[b])
        swap(a, b);
    parent[b] = a;
    if(rankk[a] == rankk[b])
        rank[a]++;
    return 0;
}

int main() {
    int i, j, x, fl, y, k, l, n, m, t, v;
    scanf("%i%i%i", &n, &m, &t);
    for(i = 1; i <= m; i++) {
        scanf("%i%i", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    q.push(t);
    used[t] = 1;
    d[t] = 1;
    l = 0;
    k = 1;
    while(!q.empty()) {
        v = q.front();
        q.pop();
        top[++l] = v;
        for(i = 0; i < g[v].size(); i++)
            if(!used[g[v][i]]) {
                used[g[v][i]] = 1;
                d[g[v][i]] = d[v] + 1;
                k = d[g[v][i]];
                q.push(g[v][i]);
            }
    }

    reverse(top+1, top+l+1);


    for(i = 1; i <= n; i++)
        if(!used[i]) {
            used[i] = 1;
            make_set(i);
            for(j = 0; j < g[i].size(); j++)
                if(used[g[i][j]])
                                 union_set(i, g[i][j]);
        }

    printf("%i\n", k);
    l = 1;
    vector <int> ans;
    memset(used, 0, sizeof(used));
    ans.push_back(kol);

    for(i = k; i >= 1; i--) {
        while(l <= n && d[top[l]] == i) {
            make_set(top[l]);
            used[top[l]] = 1;
            for(j = 0; j < g[top[l]].size(); j++)
                if(used[g[top[l]][j]])
                    union_set(top[l], g[top[l]][j]);
            l++;
        }
        ans.push_back(kol);
    }
    reverse(ans.begin(), ans.end());
    for(i = 0; i < ans.size(); i++) {
        if(i)
            printf(" ");
        printf("%i", ans[i]);
    }
    printf("\n");
    getchar();
    getchar();

    return 0;
}