#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
template<class T> void unique(vector<T> &V) {V.erase(unique(V.begin(), V.end()), V.end());}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)

template<class T, T(*e0)(), T(*e1)()>
struct matrix : vector<vector<T>>
{
  using vector<vector<T>>::vector;
  using vector<vector<T>>::operator=;

  matrix(int n, int m, T a = e0())
  {
    (*this) = vector<vector<T>>(n, vector<T>(m, 0));
    for (int i = 0; i < min(n, m); i++)
    {
      (*this)[i][i] = a;
    }
  }
  
  matrix operator-() const
  {
    int N = (*this).size(), M = (*this)[0].size();
    matrix res(*this);
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        res[i][j] = -res[i][j];
      }
    }
    return res;
  }

  matrix &operator+=(const matrix &A)
  {
    int N = (*this).size(), M = (*this)[0].size();
    assert(A.size() == N && A[0].size() == M);
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        (*this)[i][j] += A[i][j];
      }
    }
    return *this;
  }
  matrix &operator-=(const matrix &A) { return (*this) += -A; }

  matrix &operator*=(const T x)
  {
    int N = (*this).size(), M = (*this)[0].size();
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        (*this)[i][j] *= x;
      }
    }
    return *this;
  }
  matrix &operator/=(const T x)
  {
    int N = (*this).size(), M = (*this)[0].size();
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        (*this)[i][j] /= x;
      }
    }
    return *this;
  }

  friend matrix &operator*=(const T x, matrix &A) { return A *= x; }

  vector<T> operator*(const vector<T> &v)
  {
    int N = (*this).size(), M = (*this)[0].size();
    assert(v.size() == M);

    vector<T> res(N, e0());
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        res[i] += (*this)[i][j] * v[j];
      }
    }
    return res;
  }

  matrix operator*(const matrix &A)
  {
    int N = (*this).size(), M = (*this)[0].size();
    assert(A.size() == M);
    int K = A[0].size();

    matrix res(N, K, e0());
    for (int i = 0; i < N; i++)
    {
      for (int j = 0; j < M; j++)
      {
        for (int k = 0; k < K; k++)
        {
          res[i][k] += (*this)[i][j] * A[j][k];
        }
      }
    }
    return res;
  }

  matrix pow(ll k)
  {
    int N = (*this).size(), M = (*this)[0].size();
    assert(N == M);
    matrix res(N, N, e1()), tmp(*this);
    while (k > 0)
    {
      if (k & 1)
        res *= tmp;
      tmp *= tmp;
      k >>= 1;
    }
    return res;
  }

  matrix operator+(const matrix &A) const { return matrix(*this) += A; }
  matrix operator-(const matrix &A) const { return matrix(*this) -= A; }
  matrix operator*(const T x) const { return matrix(*this) *= x; }
  matrix operator/(const T x) const { return matrix(*this) /= x; }
  friend matrix operator*(const T x, matrix &A) { return A *= x; }
  matrix &operator*=(const matrix &A) { return (*this) = (*this) * A; }
};
// e0, e1 は加法, 乗法の単位元。問題によって書き換える
template <class T> constexpr T e0() { return 0; }
template <class T> constexpr T e1() { return 1; }
struct myll
{
  ll x;
  myll(ll v = 0) : x(v) {}

  // 加法, 乗法を問題によって書き換える
  myll &operator+=(myll y)
  {
    x |= y.x;
    return *this;
  }
  myll &operator*=(myll y)
  {
    x &= y.x;
    return *this;
  }

  myll operator+(myll y) const { return myll(*this) += y; }
  myll operator*(myll y) const { return myll(*this) *= y; }
};

int main()
{
  ll N, M, T;
  cin >> N >> M >> T;
  matrix<myll, e0, e1> mat(N, N);
  for (ll i = 0; i < M; i++)
  {
    ll a, b;
    cin >> a >> b;
    mat.at(b).at(a) = 1;
  }

  vector<myll> A(N, 0);
  A.at(0) = 1;
  auto B = mat.pow(T) * A;
  ll ans = 0;
  for (ll i = 0; i < N; i++)
  {
    if (B.at(i).x == 1)
      ans++;
  }
  cout << ans << endl;
}