/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//*/
 
#include <bits/stdc++.h>
 
// #include <atcoder/all>
 
using namespace std;
// using namespace atcoder;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
// #define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
void YES(bool t=true) {cout<<(t?"YES":"NO")<<endl;}
void Yes(bool t=true) {cout<<(t?"Yes":"No")<<endl;}
void yes(bool t=true) {cout<<(t?"yes":"no")<<endl;}
void NO(bool t=true) {cout<<(t?"NO":"YES")<<endl;}
void No(bool t=true) {cout<<(t?"No":"Yes")<<endl;}
void no(bool t=true) {cout<<(t?"no":"yes")<<endl;}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {0, 1, 0, -1}, dy = {-1, 0, 1, 0};
// vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
struct Setup_io {
    Setup_io() {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        cout << fixed << setprecision(25);
    }
} setup_io;
// const ll MOD = 1000000007;
// const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

ll MOD;

typedef vector<ll> vec;
typedef vector<vec> mat;

mat mul(mat &A, mat &B) {
	mat C(A.size(), vec(B[0].size()));
	for (int i = 0; i < A.size(); i++) {
		for (int k = 0; k < B.size(); k++) {
			for (int j = 0; j < B[0].size(); j++) {
				C[i][j] = C[i][j] + A[i][k] * B[k][j];
                C[i][j] %= MOD;
			}
		}
	}
	return C;
}

vec mul(mat &A, vec &B) {
	vec C(A.size());
	for (int i = 0; i < A.size(); i++) {
		for (int j = 0; j < B.size(); j++) {
			C[i] += A[i][j] * B[j];
            C[i] %= MOD;
		}
	}
	return C;
}

mat pow(mat A, ll n) {
	mat B(A.size(), vec(A.size()));
	for (int i = 0; i < A.size(); i++) {
		B[i][i] = 1;
	}
	while (n > 0) {
		if (n & 1)B = mul(B, A);
		A = mul(A, A);
		n >>= 1;
	}
	return B;
}

ll n, m, t;
vll G(100);

ll solve() {
    vec b(n);
    b[0] = 1;
    mat A(n, vec(n));
    rep (u, n) {
        for (int v: G[u]) {
            A[v][u] = 1;
        }
    }
    // DEBUG_MAT(A);
    mat An = pow(A, t);
    // DEBUG_MAT(An);

    vec goal = mul(An, b);
    ll ans = 0;
    rep (i, goal.size()) {
        if (goal[i] != 0) ans++;
    }
    return ans;
}


signed main() {
    cin >> n >> m >> t;
    rep (i, m) {
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);
    }
    
    vl temp = {1000000009, 998244353, 1000000007};
    ll ans = 0;
    rep (i, 1) {
        MOD = temp[i];
        chmax(ans, solve());
    }
    cout << ans << endl;
}