#include <fstream>
#include <vector>
#include <bitset>

using namespace std;

class InputReader
{
public:
    static const int BUFF_SIZE = 1 << 17;
    FILE *fin;
    int bp;
    char buff[BUFF_SIZE];
    InputReader (const char *file_name)
    {
        fin = fopen(file_name, "r");
        bp = BUFF_SIZE - 1;
    }
    inline void adv()
    {
        if (++bp == BUFF_SIZE)
        {
            fread(buff, sizeof(char), BUFF_SIZE, fin);
            bp = 0;
        }
    }
    InputReader& operator >> (int& num)
    {
        num = 0;
        while (isdigit(buff[bp]) == false)
            adv();
        while (isdigit(buff[bp]))
        {
            num = num * 10 + buff[bp] - '0';
            adv();
        }
        return *this;
    }
};

InputReader fin("dfs.in");
ofstream fout("dfs.out");

const int MAXN = 100005;

vector < int > v[MAXN];
bitset < MAXN > viz;

void dfs(int nod)
{
    viz[nod] = 1;
    for (auto &it : v[nod])
    {
        if (!viz[it])
        {
            dfs(it);
        }
    }
}

int main()
{
    int n, m, i, x, y, cnt = 0;
    fin >> n >> m;
    for (i = 1; i <= m; ++i)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i = 1; i <= n; ++i)
    {
        if (!viz[i])
        {
            ++cnt;
            dfs(i);
        }
    }
    fout << cnt << '\n';
    return 0;
}