#include<cstdio>
#include<vector>
using namespace std;
vector<int>L[100100];
int n,m,a,b,i,j,v[100100],nr;
FILE *f,*g;
void dfs(int nod){
    v[nod]=1;
    for(int i=0;i<L[nod].size();i++){
        if( v[ L[nod][i] ] == 0 )
            dfs( L[nod][i] );
    }
}
int main(){
    f=fopen("dfs.in","r");
    g=fopen("dfs.out","w");
    fscanf(f,"%d%d",&n,&m);
    for(i=1;i<=m;i++){
        fscanf(f,"%d%d",&a,&b);
        L[a].push_back(b);
        L[b].push_back(a);
    }
    for(i=1;i<=n;i++){
        if(v[i]==0){
            nr++;
            dfs(i);
        }
    }
    fprintf(g,"%d",nr);


    fclose(f);
    fclose(g);
    return 0;
}