import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class Main { public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String[] sa = br.readLine().split(" "); int n = Integer.parseInt(sa[0]); int m = Integer.parseInt(sa[1]); long t = Long.parseLong(sa[2]); List> list = new ArrayList<>(); for (int i = 0; i < n; i++) { list.add(new ArrayList<>()); } for (int i = 0; i < m; i++) { sa = br.readLine().split(" "); int a = Integer.parseInt(sa[0]); int b = Integer.parseInt(sa[1]); list.get(a).add(b); } br.close(); int e = 63; List>> dp = new ArrayList<>(e); List> wk = new ArrayList<>(n); for (int i = 0; i < n; i++) { Set set = new HashSet<>(); set.addAll(list.get(i)); wk.add(set); } dp.add(wk); for (int i = 1; i < e; i++) { wk = new ArrayList<>(n); List> pre = dp.get(i - 1); for (int j = 0; j < n; j++) { Set set = new HashSet<>(); Set ps = pre.get(j); for (int k : ps) { set.addAll(pre.get(k)); } wk.add(set); } dp.add(wk); } List ans = new ArrayList<>(); ans.add(0); for (int i = 0; i < e; i++) { if ((t >> i & 1) == 0) { continue; } List next = new ArrayList<>(); List> di = dp.get(i); for (int j = 0; j < n; j++) { for (int k : ans) { if (di.get(k).contains(j)) { next.add(j); break; } } } ans = next; } System.out.println(ans.size()); } }