#include <iostream>
#include <fstream>


using namespace std;

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

int n, m, x, y, nr;
bool a[1005][1005], v[1005];

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

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        a[x][y] = a[y][x] = 1;
    }
    for(int i = 1; i <= n; i++)
    {
        if(v[i] == 0)
        {
            dfs(i);
            nr ++;
        }

    }
    fout << nr;
}