#include <iostream>
#include <vector>
#define MAX_N 100005
using namespace std;

bool visited[MAX_N];
vector<int> v[MAX_N];

void dfs(int a)
{
    visited[a] = true;
    for (auto j: v[a])
        if (!visited[j])
            dfs(j);
}

int main()
{
    FILE *fin = fopen("dfs.in", "r");
    FILE *fout = fopen("dfs.out", "w");
    int n, m;
    fscanf(fin, "%d %d", &n, &m);
    for (int i = 0; i < m; i++) {
        int a, b;
        fscanf(fin, "%d %d", &a, &b);
        a--;
        b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int countt = 0;
    for (int i = 0; i < n; i++) {
        if (visited[i])
            continue;
        countt++;
        dfs(i);
    }
    fprintf(fout, "%d\n", countt);
}