#include <fstream>
#include <iostream>
#include <vector>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector<int> G[100001];
bool viz[100001];

void dfs(int nod) {
    viz[nod]=1;
    for (int vecin:G[nod]) {
        if (!viz[vecin])
            dfs(vecin);
    }
}

int main() {
    int n,m;
    f>>n>>m;
    for (int i=0;i<m;++i) {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int cc=0;
    for (int i=1;i<=n;++i) {
        if (viz[i] != 0) {
            cc++;
            dfs(i);
            
        }
    }

    g<<cc<<"\n";
    return 0;
}