#include <cstdio>
#include <vector>

using namespace std;

const int Nmax = 100002;

vector<int> v[Nmax];
bool c[Nmax];

void dfs(int x) {
    c[x] = 1;
    for (vector<int>::iterator it = v[x].begin(); it != v[x].end(); ++it)
        if (!c[*it]) dfs(*it);
}

int main() {
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    int n, m, i, k = 0, x, y;
    scanf("%d%d", &n, &m);

    for (i = 1; i <= m; ++i) {
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (i = 1; i <= n; ++i)
        if (!c[i]) ++k, dfs(i);

    printf("%d", k);

    return 0;
}