#include <bits/stdc++.h>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T, typename V>
void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }
template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }
template <typename T> bool chmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template <typename T> bool chmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; }
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
template <typename T> vector<T> sort_unique(vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T, size_t sz> ostream &operator<<(ostream &os, const array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
#if __cplusplus >= 201703L
template <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os; }
#endif
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T, typename TH> ostream &operator<<(ostream &os, const unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <typename TK, typename TV, typename TH> ostream &operator<<(ostream &os, const unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << endl
#else
#define dbg(x) (x)
#endif

// Tropical matrix
// Verify: <https://atcoder.jp/contests/ddcc2020-final/submissions/16941701>
// A[j][i] = "length of shortest parh i -> j of graph A"
// (B * A)[k][i] = min_j (B[k][j] + A[j][i])
template <typename T> struct tropical_matrix {
    constexpr static T INF = std::numeric_limits<T>::max() / 2;
    static bool _chmin(T &m, const T q) {
        if (m > q) {
            m = q;
            return true;
        }
        return false;
    }
    int H, W;
    std::vector<T> elem;
    typename std::vector<T>::iterator operator[](int i) { return elem.begin() + i * W; }
    inline T &at(int i, int j) { return elem[i * W + j]; }
    inline T get(int i, int j) const { return elem[i * W + j]; }
    operator std::vector<std::vector<T>>() const {
        std::vector<std::vector<T>> ret(H);
        for (int i = 0; i < H; i++) std::copy(elem.begin() + i * W, elem.begin() + (i + 1) * W, std::back_inserter(ret[i]));
        return ret;
    }

    tropical_matrix(int H = 0, int W = 0) : H(H), W(W), elem(H * W, INF) {}
    tropical_matrix(const std::vector<std::vector<T>> &d) : H(d.size()), W(d.size() ? d[0].size() : 0) {
        for (auto &raw : d) std::copy(raw.begin(), raw.end(), std::back_inserter(elem));
    }

    static tropical_matrix Identity(int N) {
        tropical_matrix ret(N, N);
        for (int i = 0; i < N; i++) ret.at(i, i) = 0;
        return ret;
    }

    tropical_matrix operator+(const tropical_matrix &r) const {
        tropical_matrix ret(H, W);
        for (int i = 0; i < H * W; i++) _chmin(ret.elem[i], r.elem[i]);
        return ret;
    }
    tropical_matrix operator*(const tropical_matrix &r) const {
        tropical_matrix ret(H, r.W);
        for (int i = 0; i < H; i++) {
            for (int k = 0; k < W; k++) {
                for (int j = 0; j < r.W; j++) { _chmin(ret.at(i, j), this->get(i, k) + r.get(k, j)); }
            }
        }
        return ret;
    }
    tropical_matrix &operator+=(const tropical_matrix &r) { return *this = *this + r; }
    tropical_matrix &operator*=(const tropical_matrix &r) { return *this = *this * r; }
    bool operator==(const tropical_matrix &r) const { return H == r.H and W == r.W and elem == r.elem; }
    bool operator!=(const tropical_matrix &r) const { return H != r.H or W != r.W or elem != r.elem; }
    bool operator<(const tropical_matrix &r) const { return elem < r.elem; }
    tropical_matrix pow(lint n) const {
        tropical_matrix ret = Identity(H);
        if (n == 0) return ret;
        for (int i = 63 - __builtin_clzll(n); i >= 0; i--) {
            ret *= ret;
            if ((n >> i) & 1) ret *= (*this);
        }
        return ret;
    }
    tropical_matrix transpose() const {
        tropical_matrix ret(W, H);
        for (int i = 0; i < H; i++)
            for (int j = 0; j < W; j++) ret.at(j, i) = this->get(i, j);
        return ret;
    }
    friend std::vector<T> operator*(const tropical_matrix &m, const std::vector<T> &v) {
        assert(m.W == int(v.size()));
        std::vector<T> ret(m.H, m.INF);
        for (int i = 0; i < m.H; i++) {
            for (int j = 0; j < m.W; j++) { _chmin(ret[i], m.get(i, j) + v[j]); }
        }
        return ret;
    }
    friend std::vector<T> operator*(const std::vector<T> &v, const tropical_matrix &m) {
        assert(int(v.size()) == m.H);
        std::vector<T> ret(m.W, m.INF);
        for (int i = 0; i < m.H; i++) {
            for (int j = 0; j < m.W; j++) { _chmin(ret[j], v[i] + m.get(i, j)); }
        }
        return ret;
    }
    friend std::ostream &operator<<(std::ostream &os, const tropical_matrix &x) {
        os << "[(" << x.H << " * " << x.W << " matrix)";
        for (int i = 0; i < x.H; i++) {
            os << "\n[";
            for (int j = 0; j < x.W; j++) os << x.get(i, j) << ",";
            os << "]";
        }
        os << "]\n";
        return os;
    }
    friend std::istream &operator>>(std::istream &is, tropical_matrix &x) {
        for (auto &v : x.elem) is >> v;
        return is;
    }
};

int main() {
    int N, M;
    lint T;
    cin >> N >> M >> T;
    tropical_matrix<int> mat(N, N);
    while (M--) {
        int a, b;
        cin >> a >> b;
        mat[b][a] = 0;
    }
    dbg(mat);
    auto mat2 = mat.pow(T);
    dbg(mat2);
    int ret = 0;
    REP(i, N) if (mat2.at(i, 0) == 0) ret++;
    cout << ret << '\n';
}