#include <iostream>
#include <vector>
#include <cstdio>
#define N 100005

using namespace std;

int n, m, nr, viz[N];
vector <int> graf[N];

void parcurg(int x)
{
    viz[x]=1;
    for(int i=0;i<graf[x].size();i++)
    {
        int v=graf[x][i];
        if(!viz[v])
            parcurg(v);
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d %d\n", &n, &m);
    for(int i=1;i<=m;i++)
    {
        int x, y;
        scanf("%d %d\n", &x, &y);
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            nr++;
            parcurg(i);
        }
    printf("%d", nr);
    return 0;
}