#include <cstdio>

using namespace std;
int v[10001][10001],viz[100001];
void dfs(int k)
{
    for(int j=1;j<=v[k][0];j++)
        if(viz[v[k][j]]==0)
        {
            viz[v[k][j]]=1;
            dfs(v[k][j]);
        }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    int n,m,i,j,a,b,min=0,max=0,k,sol=0;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        v[a][++v[a][0]]=b;
        v[b][++v[b][0]]=a;
    }

    k=0;
    for(k=1;k<=n;k++)
        if(viz[k]==0)
        {
            viz[k]=1;
            dfs(k);
            sol++;
        }

    printf("%d",sol);
    return 0;
}