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

vector<int>g[MAX];

int n;
bool was[MAX];

void dfs(int x){
    int y;
    was[x] = 1;
    for(int i=0;i<g[x].size();i++)
    {
        y = g[x][i];
        if( !was[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);
        }
    int nr = 0;
    for(int i=1;i<=n;i++)
    if( !was[i] )
    {
        nr++;
        dfs(i);
    }
    printf("%d\n",nr);
    return 0;
}