#include <cstdio>
#include <vector>
using namespace std;
#define MAX 100001

vector<int>g[MAX];
int n,nr;
bool viz[MAX];

void dfs(int x){
    int y;
    viz[x]=1;
    for(int i=0;i<g[x].size();i++)
    {
        y=g[x][i];
        if(!viz[y])dfs(y);
    }
}

int main(){
    int m,x,y;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
        scanf("%d %d",&n,&m);
        while(m--)
        {
            scanf("%d %d",&x,&y);
            g[x].push_back(y);
            g[y].push_back(x);
        }
    for(int i=1;i<=n;i++)
    if(!viz[i])
    {
        nr++;
        dfs(i);
    }
        printf("%d\n",nr);
    return 0;
}