#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
#define N 100001
int q[N];
vector<int> a[N];
int r[N];
bool v[N];
void FILL(int i){
    if(!v[i]){
        v[i]=1;
        for(int j=0; j<a[i].size(); ++j)
            FILL(a[i][j]);
    }
}
int main(){
    int n,m,i,x,y,s=0;
    in>>n>>m;
    for(i=1; i<=m; ++i)
        in>>x>>y, a[x].push_back(y), a[y].push_back(x);
    for(i=1; i<=n; ++i)
        if(!v[i])
            FILL(i), ++s;
    out<<s;
    return 0;
}