#include <fstream>

using namespace std;
int G[10001][10001], viz[10001], n, m, nr;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
void dfs (int k, int G[10001][10001], int viz[10001], int n) {
    viz[k] = 1;
    for (int i = 1; i <= n; ++i) {
        if(viz[i] == 0 && G[k][i] == 1) {
            dfs(i, G, viz, n);
        }
    }
}
int main()
{
    fin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y;
        fin >> x >> y;
        G[x][y] = 1;
        G[y][x] = 1;
    }
    for (int s = 1; s <= n; ++s) {
        if (viz[s] == 0) {
            nr++;
            dfs(s, G, viz, n);
        }
    }
    fout << nr;
    return 0;
}