#include <bits/stdc++.h>
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define LLA(v) (v).rbegin(), (v).rend()
#define SZ(v) (v).size()
#define INT(...)                                                               \
    int __VA_ARGS__;                                                           \
    read(__VA_ARGS__)
#define LL(...)                                                                \
    ll __VA_ARGS__;                                                            \
    read(__VA_ARGS__)
#define DOUBLE(...)                                                            \
    double __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define CHAR(...)                                                              \
    char __VA_ARGS__;                                                          \
    read(__VA_ARGS__)
#define STRING(...)                                                            \
    string __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define VEC(type, name, size)                                                  \
    vector<type> name(size);                                                   \
    read(name)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;
template <typename T> struct edge {
    int to;
    T cost;
    edge(int t, T c) : to(t), cost(c) {}
};
template <typename T> using WGraph = vector<vector<edge<T>>>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;
template <class T> inline vector<T> make_vec(size_t a, T val) {
    return vector<T>(a, val);
}
template <class... Ts> inline auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(a, make_vec(ts...));
}

void read() {}
template <class T> inline void read(T &a) { cin >> a; }
template <class T, class S> inline void read(pair<T, S> &p) {
    read(p.first), read(p.second);
}
template <class T> inline void read(vector<T> &v) {
    for(auto &a : v)
        read(a);
}
template <class Head, class... Tail>
inline void read(Head &head, Tail &...tail) {
    read(head), read(tail...);
}
template <class T> inline void chmax(T &a, T &b) { (a < b ? a = b : a); }
template <class T> inline void chmin(T &a, T &b) { (a > b ? a = b : a); }

#include <cassert>
// 参考:https://ei1333.github.io/luzhiled/snippets/math/matrix.html
// (掛け算と累乗)https://yukicoder.me/submissions/523126
// 他は知らん
template <class T> struct Matrix {
    vector<vector<T>> A;
    Matrix() {}
    Matrix(size_t n, size_t m) : A(n, vector<T>(m, 0)) {}
    Matrix(size_t n) : A(n, vector<T>(n, 0)) {}

    size_t height() const { return A.size(); }

    size_t width() const { return A[0].size(); }

    inline vector<T> &operator[](int k) { return A.at(k); }
    inline const vector<T> &operator[](int k) const { return A.at(k); }

    static Matrix I(size_t n) {
        Matrix mat(n);
        for(int i = 0; i < n; i++)
            mat[i][i] = 1;
        return mat;
    }

    Matrix &operator+=(const Matrix &B) {
        size_t h = height(), w = width();
        assert(h == B.height() && w == B.width);
        for(int i = 0; i < h; i++) {
            for(int j = 0; j < w; j++) {
                (*this)[i][j] += B[i][j];
            }
        }
        return *this;
    }

    Matrix &operator-=(const Matrix &B) {
        size_t h = height(), w = width();
        assert(h == B.height() && w == B.width);
        for(int i = 0; i < h; i++) {
            for(int j = 0; j < w; j++) {
                (*this)[i][j] -= B[i][j];
            }
        }
        return *this;
    }

    Matrix &operator*=(const Matrix &B) {
        size_t h = height(), w = B.width(), p = width();
        assert(p == B.height());
        vector<vector<T>> C(h, vector<T>(w, 0));
        for(int i = 0; i < h; i++) {
            for(int j = 0; j < w; j++) {
                for(int k = 0; k < p; k++) {
                    C[i][j] = C[i][j] || ((*this)[i][k] * B[k][j]);
                }
            }
        }
        A.swap(C);
        return *this;
    }

    Matrix &operator^=(ll k) {
        Matrix B = Matrix::I(height());
        while(k > 0) {
            if(k & 1)
                B *= *this;
            *this *= *this;
            k >>= 1LL;
        }
        A.swap(B.A);
        return *this;
    }

    Matrix operator+(const Matrix &B) const { return (Matrix(*this) += B); }
    Matrix operator-(const Matrix &B) const { return (Matrix(*this) -= B); }
    Matrix operator*(const Matrix &B) const { return (Matrix(*this) *= B); }
    Matrix operator^(const ll k) const { return (Matrix(*this) ^= k); }

    friend ostream &operator<<(ostream &os, const Matrix &p) {
        size_t h = p.height(), w = p.width();
        for(int i = 0; i < h; i++) {
            os << "[";
            for(int j = 0; j < w; j++) {
                os << p[i][j] << (j + 1 == w ? "]\n" : ",");
            }
        }
        return os;
    }
};

template <uint_fast64_t MOD> class ModInt {
    using u64 = uint_fast64_t;

  public:
    u64 val;

    ModInt(const u64 x = 0) : val((x + MOD) % MOD) {}
    constexpr u64 &value() { return val; }
    constexpr ModInt operator-() { return val ? MOD - val : 0; }
    constexpr ModInt operator+(const ModInt &rhs) const {
        return ModInt(*this) += rhs;
    }
    constexpr ModInt operator-(const ModInt &rhs) const {
        return ModInt(*this) -= rhs;
    }
    constexpr ModInt operator*(const ModInt &rhs) const {
        return ModInt(*this) *= rhs;
    }
    constexpr ModInt operator/(const ModInt &rhs) const {
        return ModInt(*this) /= rhs;
    }
    constexpr ModInt &operator+=(const ModInt &rhs) {
        val += rhs.val;
        if(val >= MOD) {
            val -= MOD;
        }
        return *this;
    }
    constexpr ModInt &operator-=(const ModInt &rhs) {
        if(val < rhs.val) {
            val += MOD;
        }
        val -= rhs.val;
        return *this;
    }
    constexpr ModInt &operator*=(const ModInt &rhs) {
        val = val * rhs.val % MOD;
        return *this;
    }

    constexpr ModInt &operator/=(const ModInt &rhs) {
        *this *= rhs.inv();
        return *this;
    }

    constexpr bool operator==(const ModInt &rhs) {
        return this->val == rhs.val;
    }
    constexpr bool operator!=(const ModInt &rhs) {
        return this->val != rhs.val;
    }
    friend constexpr ostream &operator<<(ostream &os, const ModInt<MOD> &x) {
        return os << x.val;
    }
    friend constexpr istream &operator>>(istream &is, ModInt<MOD> &x) {
        return is >> x.val;
    }

    constexpr ModInt inv() const { return ModInt(*this).pow(MOD - 2); }

    constexpr ModInt pow(ll e) const {
        u64 x = 1, p = val;
        while(e > 0) {
            if(e % 2 == 0) {
                p = (p * p) % MOD;
                e /= 2;
            } else {
                x = (x * p) % MOD;
                e--;
            }
        }
        return ModInt(x);
    }
};

using mint = ModInt<MOD>;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    INT(n, m, t);
    Matrix<bool> mat(n, n);
    rep(i, m) {
        INT(a, b);
        mat[b][a] = 1;
    }
    Matrix<bool> vec(n, 1);
    vec[0][0] = 1;
    auto res = (mat ^ t) * vec;
    int ans = 0;
    rep(i, n) if(res[i][0]) ans++;
    cout << ans << endl;
}