#include<bits/stdc++.h>
using namespace std;
#define pb push_back
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m,k;
vector <int > g[100002];
int v[100002];

    list<int> q;
void dfs(int s){
    v[s] = 1;
    for(int i = 0; i < g[s].size(); i++){
        if(v[g[s][i] ] == 0)
            dfs(g[s][i]);
    }


}

int main(){
    int x,y;
    fin>>n>>m;
    for(int i = 1; i<=m; i++){
        fin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
    }
    for(int i = 1; i<=n; i++){
        if(v[i] == 0){
            dfs(i);
            k++;
        }
    }

    fout << k;
    return 0;
}