package no3512_moesode;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int k = sc.nextInt();
		int[] in = new int[n];
		int[] out = new int[n];
		for(int i = 0;i < m;i++) {
			int a = sc.nextInt() - 1;
			int b = sc.nextInt() - 1;
			out[a]++;
			in[b]++;
		}int node = 0;
		for(int i = 0;i < n;i++) {
			if(out[i] > 0) {
				node++;
			}
		}if(node <= k) {
			int rem = k + 1 - node;
			//System.out.println(rem);
			ArrayList<Integer> num = new ArrayList<>();
			for(int i = 0;i < n;i++) {
				if(out[i] == 0) {
					num.add(in[i]);
				}
			}Collections.sort(num,Collections.reverseOrder());
			//System.out.println(num);
			long ans = 0;
			for(int i = 0;i < rem;i++) {
				ans += Math.max(0, k - num.get(i));
			}for(int i = 0;i < n;i++) {
				if(out[i] != 0) {
					ans += Math.max(0, k - in[i]);
				}
			}System.out.println(ans);
		}else {
			long ans = 0;
			for(int i = 0;i < n;i++) {
				if(out[i] != 0) {
					ans += Math.max(0,k - in[i]);
				}
			}System.out.println(ans);
		}
	}

}