#include <cstdio>
#include <vector>
using namespace std;

vector<int> list[100005];
bool viz[100005];
void parcurge(int x)
{
	viz[x]=1;
	for(unsigned int i=0;i<list[x].size();i++)
	{
		if(viz[list[x][i]]==0)
			parcurge(list[x][i]);
	}
}

int main()
{
        int n,m,nrc=0;
        freopen("dfs.in","r",stdin);
        freopen("dfs.out","w",stdout);
        scanf("%d %d",&n,&m);
        for(int i=1;i<=m;i++)
        {
			int x,y;
			scanf("%d %d",&x,&y);
			list[x].push_back(y);
			list[y].push_back(x);
        }
        for(int i=1;i<=n;i++)
        {
                if(viz[i]==0)
                {
					nrc++;
					parcurge(i);
                }
        }
        printf("%d",nrc);

        return 0;
}