// >>> TEMPLATES
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
#define int ll
#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define rep1(i,n) for (int i = 1; i <= (int)(n); i++)
#define repR(i,n) for (int i = (int)(n)-1; i >= 0; i--)
#define rep1R(i,n) for (int i = (int)(n); i >= 1; i--)
#define loop(i,a,B) for (int i = a; i B; i++)
#define loopR(i,a,B) for (int i = a; i B; i--)
#define all(x) begin(x), end(x)
#define allR(x) rbegin(x), rend(x)
#define rng(x,l,r) begin(x) + (l), begin(x) + (r)
#define pb push_back
#define eb emplace_back
#define fst first
#define snd second
template <class A, class B> auto mp(A &&a, B &&b) { return make_pair(forward<A>(a), forward<B>(b)); }
template <class... T> auto mt(T&&... x) { return make_tuple(forward<T>(x)...); }
template <class Int> auto constexpr inf = numeric_limits<Int>::max()/2-1;
auto constexpr INF32 = inf<int32_t>;
auto constexpr INF64 = inf<int64_t>;
auto constexpr INF   = inf<int>;
#ifdef LOCAL
#include "debug.hpp"
#else
#define dump(...) (void)(0)
#define say(x) (void)(0)
#define debug if (0)
#endif
template <class T, class Comp> struct pque : priority_queue<T, vector<T>, Comp> {
    vector<T> &data() { return this->c; }
    void clear() { this->c.clear(); }
};
template <class T> using pque_max = pque<T, less<T>>;
template <class T> using pque_min = pque<T, greater<T>>;
template <class T, class = typename T::iterator, enable_if_t<!is_same<T, string>::value, int> = 0>
ostream& operator<<(ostream& os, T const& a) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, size_t N, enable_if_t<!is_same<T, char>::value, int> = 0>
ostream& operator<<(ostream& os, const T (&a)[N]) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, class = decltype(begin(declval<T&>())), class = typename enable_if<!is_same<T, string>::value>::type>
istream& operator>>(istream& is, T &a) { for (auto& x : a) is >> x; return is; }
template <class T, class S> ostream& operator<<(ostream& os, pair<T, S> const& p) { return os << p.first << " " << p.second; }
template <class T, class S> istream& operator>>(istream& is, pair<T, S>& p) { return is >> p.first >> p.second; }
struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;
template <class F> struct FixPoint : private F {
    constexpr FixPoint(F&& f) : F(forward<F>(f)) {}
    template <class... T> constexpr auto operator()(T&&... x) const { return F::operator()(*this, forward<T>(x)...); }
};
struct MakeFixPoint { template <class F> constexpr auto operator|(F&& f) const { return FixPoint<F>(forward<F>(f)); } };
#define MFP MakeFixPoint()|
#define def(name, ...) auto name = MFP [&](auto &&name, __VA_ARGS__)
template <class T, size_t d> struct vec_impl {
    using type = vector<typename vec_impl<T,d-1>::type>;
    template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T,d-1>::make_v(forward<U>(x)...)); }
};
template <class T> struct vec_impl<T,0> { using type = T; static type make_v(T const& x = {}) { return x; } };
template <class T, size_t d = 1> using vec = typename vec_impl<T,d>::type;
template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T,d>::make_v(forward<Args>(args)...); }
template <class T> void quit(T const& x) { cout << x << endl; exit(0); }
template <class T, class U> constexpr bool chmin(T& x, U const& y) { if (x > y) { x = y; return true; } return false; }
template <class T, class U> constexpr bool chmax(T& x, U const& y) { if (x < y) { x = y; return true; } return false; }
template <class It> constexpr auto sumof(It b, It e) { return accumulate(b, e, typename iterator_traits<It>::value_type{}); }
template <class T> int sz(T const& x) { return x.size(); }
template <class C, class T> int lbd(C const& v, T const& x) { return lower_bound(begin(v), end(v), x)-begin(v); }
template <class C, class T> int ubd(C const& v, T const& x) { return upper_bound(begin(v), end(v), x)-begin(v); }
const int dx[] = { 1,0,-1,0,1,-1,-1,1 };
const int dy[] = { 0,1,0,-1,1,1,-1,-1 };
constexpr int popcnt(ll x) { return __builtin_popcountll(x); }
// [a,b]
template <class Int> Int rand(Int a, Int b) { static mt19937_64 mt{random_device{}()}; return uniform_int_distribution<Int>(a,b)(mt); }
i64 irand(i64 a, i64 b) { return rand<i64>(a,b); }
u64 urand(u64 a, u64 b) { return rand<u64>(a,b); }
template <class It> void shuffle(It l, It r) { shuffle(l, r, mt19937_64(random_device{}())); }
// <<<
// >>> semi-ring
struct SemiRing {
    using T = bool;
    T a;
    SemiRing() { *this = zero(); }
    SemiRing(T a) : a(a) {}
    T val() const { return a; }
    static SemiRing zero() { return 0; }
    static SemiRing one() { return 1; }
    SemiRing operator*(SemiRing const& r) const {
        if (*this == zero() || r == zero()) return zero();
        if (*this == one()) return r;
        if (r == one()) return *this;
        return a & r.a;
    }
    SemiRing operator+(SemiRing const& r) const {
        if (*this == zero()) return r;
        if (r == zero()) return *this;
        return a or r.a;
    }
    SemiRing& operator*=(SemiRing const& r) { return *this = (*this)*r; }
    SemiRing& operator+=(SemiRing const& r) { return *this = (*this)+r; }
    bool operator==(SemiRing const& r) const { return a == r.a; }
    friend ostream& operator<<(ostream& os, SemiRing const& x) {
        return os << x.a;
    }
};
#ifdef LOCAL
string to_s(SemiRing const& x) { return to_s(x.a); }
#endif
// <<<

template <class T> T semi_ring_one() { return 1; }
template <> SemiRing semi_ring_one() { return SemiRing::one(); }

// >>> matrix using 1d vector
template <class T> struct Matrix {
    int n, m;
    vector<T> a;
    Matrix() {}
    Matrix(int n, int m) : n(n), m(m), a(n*m) {
        assert(n > 0 && m > 0);
    }
    Matrix(initializer_list<initializer_list<T>> init) {
        n = init.size();
        assert(n > 0);
        m = init.begin()->size();
        assert(m > 0);
        a.resize(n*m);
        int i = 0;
        for (auto const& ls : init) {
            assert((int)ls.size() == m);
            for (auto const& x : ls) {
                a[i++] = x;
            }
        }
    }
    auto operator[](int i) const {
        assert(0 <= i); assert(i < n);
        return a.begin() + i*m;
    }
    auto operator[](int i) {
        assert(0 <= i); assert(i < n);
        return a.begin() + i*m;
    }
    bool operator==(Matrix const& x) const {
        if (n != x.n || m != x.m) return false;
        rep (i, n) rep (j, m) if ((*this)[i][j] != x[i][j]) return false;
        return true;
    }
    bool operator!=(Matrix const& x) const {
        return !(*this == x);
    }
	Matrix operator+() const { return *this; }
    Matrix operator+(Matrix const& x) const { return Matrix(*this) += x; }
    Matrix& operator+=(Matrix const& x) {
        assert(n == x.n && m == x.m);
        rep (i, n) rep (j, m) (*this)[i][j] += x[i][j];
        return *this;
    }
    Matrix operator*(Matrix const& x) const {
        assert(m == x.n);
        Matrix ret(n, x.m);
        rep (i, n) rep (j, m) rep (k, x.m) ret[i][k] += (*this)[i][j] * x[j][k];
        return ret;
    }
    Matrix& operator*=(Matrix const& x) {
        auto res = (*this)*x;
        swap(a, res.a);
        return *this;
    }
    Matrix operator*(T const& c) const { return Matrix(*this) *= c; }
    Matrix& operator*=(T const& c) {
        rep (i, n) rep (j, m) (*this)[i][j] *= c;
        return *this;
    }
    friend Matrix operator*(T const& c, Matrix const& x) {
        Matrix ret = x;
        rep (i, x.n) rep (j, x.m) ret[i][j] = c*x[i][j];
        return ret;
    }
    static Matrix identity(int n) {
        Matrix ret(n, n);
        rep (i, n) ret[i][i] = 1;
        return ret;
    }
    Matrix pow(ll k) const {
        assert(n == m); assert(k >= 0);
        Matrix v = *this, r = Matrix::identity(n);
        for (; k > 0; k >>= 1, v *= v) if (k&1) r *= v;
        return r;
    }
#if 1
	Matrix operator-() const {
		Matrix x = *this;
        rep (i, n) rep (j, m) x[i][j] = -x[i][j];
		return x;
	}
    Matrix& operator-=(Matrix const& x) {
        assert(n == x.n && m == x.m);
        rep (i, n) rep (j, m) (*this)[i][j] -= x[i][j];
        return *this;
    }
    Matrix operator-(Matrix const& x) const { return Matrix(*this) -= x; }
    Matrix& operator/=(T const& c) {
        rep (i, n) rep (j, m) (*this)[i][j] /= c;
        return *this;
    }
    Matrix operator/(T const& c) const {
        return Matrix(*this) /= c;
    }
#endif
    friend istream& operator>>(istream& is, Matrix& x) {
        rep (i, x.n) rep (j, x.m) is >> x[i][j];
        return is;
    }
#ifdef LOCAL
    friend string to_s(Matrix const& x) {
        string ret;
        rep (i, x.n) {
            ret += "\n(";
            rep (j, x.m) ret += " " + to_s(x[i][j]);
            ret += " )";
        }
        return ret += "\n";
    }
#endif
};
// <<<

using Mat = Matrix<SemiRing>;

int32_t main() {
    int n, m, t; cin >> n >> m >> t;

    Mat A(n, n);
    rep (i, m) {
        int a, b; cin >> a >> b;
        A[a][b] = 1;
    }

    A = A.pow(t);
    int ans = 0;
    rep (i, n) if (A[0][i].val()) ans++;
    cout << ans << "\n";


}