#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
using VS = vector<string>;
template<class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i,a,n) for(int i=(a);i<(n);++i)
#define eFOR(i,a,n) for(int i=(a);i<=(n);++i)
#define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i)
#define erFOR(i,a,n) for(int i=(n);i>=(a);--i)
#define SORT(a) sort(a.begin(),a.end())
#define rSORT(a) sort(a.rbegin(),a.rend())
#define fSORT(a,f) sort(a.begin(),a.end(),f)
#define all(a) a.begin(),a.end()
#define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x))
#define tp(a,i) get<i>(a)
#ifdef _DEBUG
#define line cout << "-----------------------------\n"
#define stop system("pause")
#define debug(x) print(x)
#endif
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10;
constexpr ld pi = 3.1415926535897932;
template<class T>inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; }
template<class T>inline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; }
inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }
template<class T>inline istream& operator>>(istream& is, vector<T>& v) { for (auto& a : v)is >> a; return is; }
template<class T, class U>inline istream& operator>>(istream& is, pair<T, U>& p) { is >> p.first >> p.second; return is; }
template<class T>inline vector<T> vec(size_t a) { return vector<T>(a); }
template<class T>inline vector<T> defvec(T def, size_t a) { return vector<T>(a, def); }
template<class T, class... Ts>inline auto vec(size_t a, Ts... ts) { return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...)); }
template<class T, class... Ts>inline auto defvec(T def, size_t a, Ts... ts) { return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...)); }
template<class T>inline void print(const T& a) { cout << a << "\n"; }
template<class T, class... Ts>inline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); }
template<class T>inline void print(const vector<T>& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); }
template<class T>inline void print(const vector<vector<T>>& v) { for (auto& a : v)print(a); }
inline string reversed(const string& s) { string t = s; reverse(all(t)); return t; }
template<class T>inline T sum(const vector<T>& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); }
template<class T>inline void END(T s) { print(s); exit(0); }
void END() { exit(0); }

struct matrix {
    int n, m;
    vector<vector<bool>> dat;
    matrix(const vector<vector<bool>>& _a) : dat(_a) {
        n = dat.size(), m = dat.front().size();
    }
    matrix(const int& _n, const int& _m) : n(_n), m(_m) {
        dat = vec<bool>(n, m);
    }
    matrix() {}

    matrix operator*=(const matrix& a) {
        assert(m == a.n);
        matrix ret(vec<bool>(n, a.m));
        FOR(i, 0, n)FOR(k, 0, m)FOR(j, 0, a.m) {
            ret[i][j] = ret[i][j] || (dat[i][k] && a.dat[k][j]);
        }
        return *this = ret;
    }
    matrix operator*(const matrix& a) { return matrix(*this) *= a; }

    matrix pow(ll k) const {
        assert(n == m);
        matrix ret(vec<bool>(n, n)), a(dat);
        FOR(i, 0, n)ret[i][i] = true;
        for (; 0 < k; k >>= 1) {
            if (k & 1)ret *= a;
            a *= a;
        }
        return ret;
    }
    vector<bool>& operator[](int i) { return dat[i]; }
};

int main() {
    init();

    int n, m; ll t; cin >> n >> m >> t;
    matrix mat(n, n);
    FOR(i, 0, m) {
        int a, b; cin >> a >> b;
        mat[a][b] = true;
    }
    matrix cur(n, n);
    cur[0][0] = true;
    auto mul = cur * mat.pow(t);
    int ans = 0;
    FOR(j, 0, n)if (mul[0][j])++ans;
    print(ans);

    return 0;
}