#include <bits/stdc++.h>
#define MAXN 100001
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,m,s;
vector<int> v[MAXN];
stack<int> st;
bool f[MAXN];
void dfs(int start)
{
    f[start]=1;
    for(int i: v[start])
    {
        if(!f[i])
            dfs(i);
    }
}
int main()
{
    in>>n>>m;
    for(int i=1; i<=m; ++i)
    {
        int x,y;
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; ++i)
    {
        if(!f[i])
        {
            s++;
            dfs(i);
        }
    }
    out<<s;
    return 0;
}