bfs

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

#define MAXPEEKSNR 100
int peeks, links;
vector<int> graph[MAXPEEKSNR];

int bfs(int startNode)
{
    queue<int> bfsQueue;
    vector<bool> visited(peeks + 1, false);
    unsigned visnr = 0;

    bfsQueue.push(startNode);
    visited[startNode] = true;

    while (!bfsQueue.empty())
    {
        int currNode = bfsQueue.front();
        bfsQueue.pop();
        for (int i = 0; i < (int)graph[currNode].size(); i++)
        {
            if (!visited[graph[currNode][i]])
            {
                visited[graph[currNode][i]] = true;
                bfsQueue.push(graph[currNode][i]);
            }
        }
        //cerr << currNode << ' ';
        visnr++;
    }
    return visnr;
}

int main()
{
    cin >> peeks >> links;
    int node;
    for (int i = 0; i < links; i++)
    {
        int x, y;
        cin >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
        node = x;
    }

    int visnr = bfs(node);
    cout << endl << visnr;

    return 0;
}