#include <bits/stdc++.h>

#if 1
#define pv(x) cout<<#x<<" = "<<x<<"; ";cout.flush()
#define pn cout<<endl
#else
#define pv(x)
#define pn
#endif

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

using ll = long long;
using ull = unsigned long long;
using uint = unsigned int;
#define pb push_back
const int NMax = 1e5 + 5;
const int inf = 1e9 + 5;
using zint = int;

int N,M;
bool vis[NMax];
vector<int> v[NMax];

void dfs(int node) {
    vis[node] = true;

    for (int nxt : v[node]) {
        if (vis[nxt]) {
            continue;
        }

        dfs(nxt);
    }
}

int main() {
    in>>N>>M;
    for (int i = 1;i <= M;++i) {
        int x,y;
        in>>x>>y;

        v[x].pb(y);
        v[y].pb(x);
    }

    int ans = 0;
    for (int i = 1;i <= N;++i) {
        if (vis[i]) {
            continue;
        }

        ++ans;
        dfs(i);
    }

    out<<ans;

    in.close();out.close();
    return 0;
}