#include <bits/stdc++.h>

using namespace std;

int a[1005][1005], n , m, viz[1005],cnt;

void DFS(int nod)
{
    int i;
    viz[nod] = 1;
    for(int i = 1;i<=n;i++) if(!viz[i] && a[nod][i]) DFS(i);
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    int x,y;
    for(int i = 1;i<=m;i++)
    {
        fin >> x >> y;
        a[x][y] = a[y][x] = 1;
    }
    for(int i = 1;i<=n;i++) if(!viz[i]) cnt++,DFS(i);
    fout << cnt;
    return 0;
}