#include <bits/stdc++.h>
using namespace std;
#define nmax 100000
ifstream f("dfs.in");
ofstream g("dfs.out");

vector<int>a[nmax+5];
vector<int>v(nmax+5,0);

void dfs(int k){
    v[k]=1;
    for(auto i : a[k])
        if(v[i]==0)dfs(i);
}

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