#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)n; ++i)
#define rrep(i, n) for (int i = (int)n-1; i >= 0; --i)
using namespace std;
using ll = long long;
template<typename T>
inline bool chmax(T& a, const T& b) {
    if (a < b){
        a = b;
        return true;
    }
    return false;
}
template<typename T>
inline bool chmin(T& a, const T& b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
/**
 * @brief 多次元 vector の作成
 * @author えびちゃん
 */
namespace detail {
    template<typename T, int N>
    auto make_vec(vector<int>& sizes, T const& x) {
        if constexpr (N == 1) {
            return vector(sizes[0], x);
        } else {
            int size = sizes[N-1];
            sizes.pop_back();
            return vector(size, make_vec<T, N-1>(sizes, x));
        }
    }
}
template<typename T, int N>
auto make_vec(int const(&sizes)[N], T const& x = T()) {
    vector<int> s(N);
    for (int i = 0; i < N; ++i) s[i] = sizes[N-i-1];
    return detail::make_vec<T, N>(s, x);
}
__attribute__((constructor))
void fast_io() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

template <typename T>
struct matrix {
    using vec = vector<T>;
    using mat = vector<vec>;
    
    mat M;
    
    matrix(size_t r, size_t c) : M(r, vec(c)) {}
    matrix(mat M) : M(M) {}

    size_t size() const { return M.size();}
    vec& operator[](size_t i) { return M[i];}
    const vec& operator[](size_t i) const { return M[i];};
    static matrix cross(const matrix& A, const matrix& B) {
        matrix res(A.size(), B[0].size());
        for (int i = 0; i < (int)A.size(); ++i)
            for (int j = 0; j < (int)B[0].size(); ++j)
                for (int k = 0; k < (int)B.size(); ++k)
                    res[i][j] |= A[i][k] & B[k][j];
        return res;
    }

    static matrix identity(size_t n) {
        matrix res(n, n);
        for (int i = 0; i < (int)n; ++i) res[i][i] = 1;
        return res;
    }

    matrix pow(long long n) const {
        matrix A(M), res = identity(size());
        while (n > 0) {
            if (n & 1) res = cross(res, A);
            A = cross(A, A);
            n >>= 1;
        }
        return res;
    }
};

int main() {
    int n, m;
    ll t;
    cin >> n >> m >> t;
    matrix<int> mat(n, n);
    rep(i, m) {
        int a, b;
        cin >> a >> b;
        mat[b][a] = 1;
    }
    mat = mat.pow(t);
    int ans = 0;
    rep(i, n) ans += mat[i][0];
    cout << ans << '\n';
}