#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,m,p,x,y,i,ok,nr,v[100001],c[100001];
vector <int> L[100001];

int 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(){
    fin>>n>>m>>p;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        ok=1;
        if(x==y)
            ok=0;
        for(int j=0;j<L[x].size();j++)
            if(y==L[x][j])
                ok=0;
        if(ok){
            L[x].push_back(y);
            L[y].push_back(x);
        }
    }

    for(i=1;i<=n;i++)
        if(v[i]==0){
            ++nr;
            dfs(i);
        }
    fout<<nr;
}