#include using namespace std; using int64 = long long; const int mod = 1e9 + 7; //const int mod = 998244353; const int64 infll = (1LL << 62) - 1; const int inf = (1 << 30) - 1; struct IoSetup { IoSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup; template< typename T1, typename T2 > ostream &operator<<(ostream &os, const pair< T1, T2 > &p) { os << p.first << " " << p.second; return os; } template< typename T1, typename T2 > istream &operator>>(istream &is, pair< T1, T2 > &p) { is >> p.first >> p.second; return is; } template< typename T > ostream &operator<<(ostream &os, const vector< T > &v) { for(int i = 0; i < (int) v.size(); i++) { os << v[i] << (i + 1 != v.size() ? " " : ""); } return os; } template< typename T > istream &operator>>(istream &is, vector< T > &v) { for(T &in : v) is >> in; return is; } template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } template< typename T = int64 > vector< T > make_v(size_t a) { return vector< T >(a); } template< typename T, typename... Ts > auto make_v(size_t a, Ts... ts) { return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...)); } template< typename T, typename V > typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) { t = v; } template< typename T, typename V > typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) { for(auto &e : t) fill_v(e, v); } template< typename F > struct FixPoint : F { FixPoint(F &&f) : F(forward< F >(f)) {} template< typename... Args > decltype(auto) operator()(Args &&... args) const { return F::operator()(*this, forward< Args >(args)...); } }; template< typename F > inline decltype(auto) MFP(F &&f) { return FixPoint< F >{forward< F >(f)}; } /** * @brief Square-Matrix(正方行列) */ template< class T, size_t N > struct SquareMatrix { array< array< T, N >, N > A; SquareMatrix() = default; size_t size() { return N; } inline const array< T, N > &operator[](int k) const { return (A.at(k)); } inline array< T, N > &operator[](int k) { return (A.at(k)); } static SquareMatrix add_identity() { return SquareMatrix(); } static SquareMatrix mul_identity() { SquareMatrix mat; for(size_t i = 0; i < N; i++) mat[i][i] = 1; return mat; } SquareMatrix &operator+=(const SquareMatrix &B) { for(size_t i = 0; i < N; i++) { for(size_t j = 0; j < N; j++) { (*this)[i][j] += B[i][j]; } } return *this; } SquareMatrix &operator-=(const SquareMatrix &B) { for(size_t i = 0; i < N; i++) { for(size_t j = 0; j < N; j++) { (*this)[i][j] -= B[i][j]; } } return *this; } SquareMatrix &operator*=(const SquareMatrix &B) { array< array< T, N >, N > C; for(size_t i = 0; i < N; i++) { for(size_t j = 0; j < N; j++) { C[i][j] = 0; for(size_t k = 0; k < N; k++) { C[i][j] = (C[i][j] + (*this)[i][k] * B[k][j]); chmin(C[i][j], 1); } } } A.swap(C); return (*this); } SquareMatrix &operator^=(uint64_t k) { SquareMatrix B = SquareMatrix::mul_identity(); while(k > 0) { if(k & 1) B *= *this; *this *= *this; k >>= 1LL; } A.swap(B.A); return *this; } SquareMatrix operator+(const SquareMatrix &B) const { return SquareMatrix(*this) += B; } SquareMatrix operator-(const SquareMatrix &B) const { return SquareMatrix(*this) -= B; } SquareMatrix operator*(const SquareMatrix &B) const { return SquareMatrix(*this) *= B; } SquareMatrix operator^(uint64_t k) const { return SquareMatrix(*this) ^= k; } friend ostream &operator<<(ostream &os, SquareMatrix &p) { for(int i = 0; i < N; i++) { os << "["; for(int j = 0; j < N; j++) { os << p[i][j] << (j + 1 == N ? "]\n" : ","); } } return os; } }; int main() { int N, M; int64 T; cin >> N >> M >> T; auto mat = SquareMatrix< int, 100 >::add_identity(); for(int i = 0; i < M; i++) { int a, b; cin >> a >> b; mat[a][b] = 1; } mat ^= T; int ret = 0; for(int i = 0; i < N; i++) { ret += mat[0][i]; } cout << ret << "\n"; }