#include <iostream>
#include <fstream>

using namespace std;

int n,m,x,y,k,viz[1007];
bool a[1007][1007];

void dfs(int i)
{
    if(viz[i]==0)
    {
        viz[i]=1;
        for(int j=1;j<=n;j++)
        {
            if(viz[j]==0 && a[i][j]==1)
                dfs(j);
        }
    }
}
int main()
{
    int i,j;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>x;
        cin>>y;
        a[x][y]=1;
        a[y][x]=1;
    }
    /*
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=n;j++)
            cout<<a[i][j]<<" ";
        cout<<"\n";
    }*/
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            dfs(i);k++;
        }
    }
    cout<<k<<"\n";
    return 0;
}