#include <fstream>
#define cin fin
#define cout fout

using namespace std;

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

int n, m, sol;
bool A[101][101], viz[101];

void citire()
{
    int x, y;
    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        cin >> x >> y;
        A[x][y] = A[y][x] = 1;
    }
}

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

int main()
{
    citire();
    for(int i = 1; i <= n; i++)
        if(!viz[i])
        {
            ++sol;
            dfs(i);
        }
    cout << sol;
    return 0;
}