#include <bits/stdc++.h>

#define INF 99999999

#define DIM 100000

using namespace std;

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

//ifstream f("filesmodel.in");
//ofstream g("filesmodel.out");

int n,m;
int x,y;
vector <int> L[DIM+5];
int v[DIM+5];
bool u[DIM+5];

int sol = 0;

void dfs(int nod){

    u[nod] = 1;
    for(auto vec:L[nod]){
        if(u[vec]){
            continue;
        }
        dfs(vec);
    }
}

signed main(){

    f>>n>>m;
    for(int i=1;i<=m;i++){
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

    for(int i=1;i<=n;i++){
        if(!u[i]){
            dfs(i);
            sol++;
        }
    }

    g<<sol;

    return 0;
}