#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  constexpr int X = 60;
  int n, m; ll t; cin >> n >> m >> t;
  vector graph(n, vector(n, false));
  while (m--) {
    int a, b; cin >> a >> b;
    graph[a][b] = true;
  }
  vector dp(X, vector(n, vector(n, false)));
  dp[0] = graph;
  FOR(i, 1, X) REP(j, n) REP(k, n) {
    if (dp[i - 1][j][k]) {
      REP(l, n) {
        if (dp[i - 1][k][l]) dp[i][j][l] = true;
      }
    }
  }
  vector<bool> reach(n, false);
  reach[0] = true;
  REP(b, X) {
    if (t >> b & 1) {
      vector<bool> nx(n, false);
      REP(i, n) {
        if (reach[i]) {
          REP(j, n) {
            if (dp[b][i][j]) nx[j] = true;
          }
        }
      }
      reach.swap(nx);
    }
  }
  cout << count(ALL(reach), true) << '\n';
  return 0;
}