#include <bits/stdc++.h>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,nr;
vector <int> a[100001];
int vf[100001];

void dfs(int x){
    vf[x]=1;
    for(int i:a[x])
        if(!vf[i])
        dfs(i);
}

int main()
{
    f>>n>>m;
    for(int i=1; i<=m; i++){
        int x,y;
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!vf[i])
        dfs(i), nr++;
    g<<nr;
    return 0;
}