#include<cstdio>
#include<vector>
using namespace std;
vector<int> L[100100];
int n,m,i,j,nr,v[100100],x,y;
FILE *f,*g;
void dfs(int nod){
    int i;
    v[nod]=1;
    for(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",&x,&y);
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1;i<=n;i++){
        if(v[i]==0){
            nr++;
            dfs(i);
        }
    }
    fprintf(g,"%d",nr);
    fclose(f);
    fclose(g);
    return 0;
}