#include <stdio.h>
#include <vector>
using namespace std;
vector <int> g[100002];
int viz[100002],n,m;

void citire()
{
    freopen("dfs.in","r",stdin);
    scanf("%d %d",&n,&m);
    int i,x,y;
    for (i=1;i<=m;++i)
    {
        scanf("%d %d",&x,&y);
     g[x].push_back(y);
     g[y].push_back(x);
    }

}
void dfs(int x)
{int i;
    viz[x]=1;
    for(i=0;i<g[x].size();++i)
            if (viz[g[x][i]]==0) dfs(g[x][i]);
        }
int main()
{int i,nr=0;
    citire();
        for(i=1;i<=n;++i)

        if (viz[i]==0)
        {
                        dfs(i);
                        ++nr;
        }
    freopen("dfs.out","w",stdout);
    printf("%d",nr);

    return 0;
}