#include <cstdio>
#include <vector>
using namespace std;
vector <int> g[100001];
bool ok[100001];
void dfs (int x)
{
    int i, y; ok[x]=true;
    for (i=0; i<g[x].size(); i++)
    {
        y=g[x][i];
        if (!ok[y]) dfs(y);
    }
}
int main()
{
    int n, m, i, x, y, nr=0;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1; i<=m; i++)
    {
        scanf("%d%d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for (i=1; i<=n; i++)
    {
        if (!ok[i])
        {
            nr++;
            dfs(i);
        }
    }
    printf("%d\n",nr);
    return 0;
}