#include <fstream>

using namespace std;

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

int a[1003][1003], viz[1003], n, m;

void dfs (int nod)
{
    viz[nod] = 1;
    for(int i = 1; i <= n; i++)
    {
        if(a[nod][i] == 1 && viz[i] == 0)
            dfs(i);
    }
}

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