#include <cstdio>
#include <vector>

using namespace std;

vector<int> v[100001];

int n, m;

bool fost[100001];

void dfs(int x) {
    if (fost[x]) {
        return;
    }
    fost[x] = true;
    for (int i = 0; i < v[x].size(); ++i) {
        dfs(v[x][i]);
    }
}

int main() {
    FILE* f = fopen("dfs.in", "r");
    FILE* h = fopen("dfs.out", "w");
    fscanf(f, "%d%d", &n, &m);
    for (int i = 1; i <= m; ++i) {
        int x, y;
        fscanf(f, "%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int k = 0;
    for (int i = 1; i <= n; ++i) {
        if (!fost[i]) {
            ++k;
            dfs(i);
        }
    }
    fprintf(h,"%d\n", k);
    return 0;
}