#include <cstdio>
#include <vector>
using namespace std;
#define nmax 100001

vector <int> v[nmax];
int n, m, nr=0, viz[nmax]={0};

void dfs(int nod)
{
    int j;
    viz[nod]=1;
    for (j=0; j<v[nod].size(); j++)
        if ( viz[ v[nod][j] ] == 0)
        {
            dfs( v[nod][j] );
        }
}

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