#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>

FILE *fin = fopen("dfs.in", "r");
FILE *fout = fopen("dfs.out", "w");

#define MAXN 100000

std::vector <int> v[MAXN + 1];
bool viz[MAXN + 1];

void dfs(int i) {
    viz[i] = 1;
    int k = v[i].size();
    for (int j = 0; j < k; j++)
        if (viz[v[i][j]] == 0)
            dfs(v[i][j]);
}

int main()
{
    int m, n, nr = 0, x, y;
    fscanf(fin, "%d%d", &n, &m);
    for (int i = 1; i <= m; i++) {
        fscanf(fin, "%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) {
        if (viz[i] == 0) {
            dfs(i);
            nr++;
        }

    }
    fprintf(fout, "%d", nr);
    return 0;
}