#include<iostream>
#include<fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int c[100],v[100],a[100][100],p=1,n,m,con=0;
int dfs(int nod)
{int i;
    v[nod]=1;
    for (i=1;i<=n;i++)
        if(v[i]==0 && a[nod][i]==1)
            dfs(i);
}
int main()
{
    int i,j,k,z;
    f>>n>>m;
    for(i=1;i<=m;i++)
           {f>>z>>k;
           a[z][k]=1;
           a[k][z]=1;}
          int q=0;
          int nod=1;
           i=1;
           while(i<=n)
          {dfs(i);con++;
            while(v[i]!=0 && i<=n)
                    i++;
          }
          g<<con;
}