#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cmath>
using namespace std;
using ll = long long;

template <class T>
struct Matrix {
    Matrix(int n, int m) : a(n * m), n(n), m(m) {}
    static Matrix E(int n) {
        Matrix r(n, n);
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                r[i][j] = i == j;
            }
        }
        return r;
    }
    Matrix pow(ll k) const {
        Matrix r = E(n), t = *this;
        for (; k != 0; k /= 2) {
            if (k & 1) r = r * t;
            t = t * t;
        }
        return r;
    }
    Matrix operator*(const Matrix &x) const {
        if (m != x.n) throw;
        Matrix r(n, x.m);
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < x.m; j++) {
                T t = 0;
                for (int k = 0; k < m; k++) {
                    t |= (*this)[i][k] & x[k][j];
                }
                r[i][j] = t;
            }
        }
        return r;
    }
    const T *operator[](int i) const {
        return &a[i * m];
    }
    T *operator[](int i) {
        return &a[i * m];
    }
    vector<T> a;
    int n, m;
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, m;
    cin >> n >> m;

    ll t;
    cin >> t;

    Matrix<char> v(n, 1), x(n, n);
    v[0][0] = 1;

    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;

        x[b][a] = 1;
    }

    v = x.pow(t) * v;

    int r = 0;
    for (int i = 0; i < n; i++) {
        r += v.a[i];
    }

    cout << r << endl;

    return 0;
}