#include <bits/stdc++.h>

using namespace std;

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

int const lim =100001;
int n,m,t;
bool ver[lim];
vector < int > c[lim];

void dfs(int nod)
{
    ver[nod]=1;

    for(int i=0;i<c[nod].size();i++)
        if(ver[c[nod][i]]==0)
        dfs(c[nod][i]);
}

int main()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        in>>x>>y;
        c[x].push_back(y);
        c[y].push_back(x);
    }

    for(int i=1;i<=n;i++)
        if(ver[i]==0)
    {
        t++;
        dfs(i);
    }

    out<<t;
}