#include <bits/stdc++.h>
#define be(v) (v).begin(),(v).end()
#define pb(q) push_back(q)
typedef long long ll;
using namespace std;
const ll mod=1000000007, INF=(1LL<<60);
#define doublecout(a) cout<<fixed<<setprecision(10)<<a<<endl;




///////modint
struct mint {
    ll x; // typedef long long ll;
    mint(ll x=0):x((x%mod+mod)%mod){}
    mint operator-() const { return mint(-x);}
    mint& operator+=(const mint a) {
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator-=(const mint a) {
        if ((x += mod-a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
    mint operator+(const mint a) const { return mint(*this) += a;}
    mint operator-(const mint a) const { return mint(*this) -= a;}
    mint operator*(const mint a) const { return mint(*this) *= a;}
    mint pow(ll t) const {
        if (!t) return 1;
        mint a = pow(t>>1);
        a *= a;
        if (t&1) a *= *this;
        return a;
    }

    // for prime mod
    mint inv() const { return pow(mod-2);}
    mint& operator/=(const mint a) { return *this *= a.inv();}
    mint operator/(const mint a) const { return mint(*this) /= a;}
};



///////Matrix
template<class T> struct Matrix {
    vector<vector<T> > val;
    //　縦, 横, 初期値
    Matrix(int n = 1, int m = 1, T v = 0) : val(n, vector<T>(m, v)) {}
    void init(int n, int m, T v = 0) {val.assign(n, vector<T>(m, v));}
    Matrix<T>& operator = (const Matrix<T> &A) {
        val = A.val; return *this;
    }
    size_t size() const {return val.size();}
    vector<T>& operator [] (int i) {return val[i];}
    const vector<T>& operator [] (int i) const {return val[i];}
    friend ostream& operator << (ostream& s, const Matrix<T>& M) {
        s << endl;
        for (int i = 0; i < (int)M.size(); ++i) s << M[i] << endl;
        return s;
    }
};

template<class T> Matrix<T> operator * (const Matrix<T> &A, const Matrix<T> &B) {
    Matrix<T> R(A.size(), B[0].size());
    for (int i = 0; i < A.size(); ++i)
        for (int j = 0; j < B[0].size(); ++j)
            for (int k = 0; k < B.size(); ++k)
                R[i][j] += A[i][k] * B[k][j];
    return R;
}

template<class T> Matrix<T> pow(const Matrix<T> &A, long long n) {
    Matrix<T> R(A.size(), A.size());
    auto B = A;
    for (int i = 0; i < A.size(); ++i) R[i][i] = 1;
    while (n > 0) {
        if (n & 1) R = R * B;
        B = B * B;
        n >>= 1;
    }
    return R;
}

template<class T> vector<T> operator * (const Matrix<T> &A, const vector<T> &B) {
    vector<T> v(A.size());
    for (int i = 0; i < A.size(); ++i)
        for (int k = 0; k < B.size(); ++k)
            v[i] += A[i][k] * B[k];
    return v;
}

template<class T> Matrix<T> operator + (const Matrix<T> &A, const Matrix<T> &B) {
    Matrix<T> R(A.size(), A[0].size());
    for (int i = 0; i < A.size(); ++i)
        for (int j = 0; j < A[0].size(); ++j)
            R[i][j] = A[i][j] + B[i][j];
    return R;
}

template<class T> Matrix<T> operator - (const Matrix<T> &A, const Matrix<T> &B) {
    Matrix<T> R(A.size(), A[0].size());
    for (int i = 0; i < A.size(); ++i)
        for (int j = 0; j < A[0].size(); ++j)
            R[i][j] = A[i][j] - B[i][j];
    return R;
}


int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);
    ll n, m, t;
    cin >> n >> m >> t;
    Matrix<mint> mat(n, n, 0);
    int a, b;
    for(int i=0;i<m;i++){
        cin >> a >> b;
        mat[b][a] = 1;
    }
    mat = pow(mat, t);
    int ans = 0;
    for(int i=0;i<n;i++) if(mat[i][0].x > 0) ans++;
    cout << ans << endl;

    return 0;
}