#include <bits/stdc++.h>
#include <queue>
using namespace std;
using ll=long long;
int main(){
  ll n,m,k; cin>>n>>m>>k;
  ll c[n],d[n];
  for(int i=0; i<m; i++){
    ll a,b; cin>>a>>b;
    c[a-1]++; d[b-1]++;
  }
  ll memo=0;
  for(int i=0; i<n; i++){
    if(c[i]!=0){
      memo++;
    }
  }
  ll ans=0;
  vector<int> e;
  for(int i=0; i<n; i++){
    if(c[i]!=0){
      ans+=max(0LL,k-d[i]);
    }
    else{
      e.push_back(max(0LL,k-d[i]));
    }
  }
  sort(e.begin(),e.end());
  if(memo<=k){
    memo=k+1-memo;
    for(int i=0; i<memo; i++){
      ans+=e[i];
    }
  }
  cout<<ans<<endl;
}