#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
#include <cctype>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <utility>
#include <fstream>

using namespace std;
typedef long long ll;
using ull = unsigned long long;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//template<typename T> T gcd(T a, T b) { a = abs(a), b = abs(b); while (b > 0) { tie(a, b) = make_pair(b, a % b); }return a; }
//mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
//constexpr long long mod = 1000000007LL;
constexpr long long  mod = 998244353;

int main()
{

	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	int n, m;
	ll T; cin >> n >> m >> T;
	constexpr int size = 100;
	static array<bitset<size>, size> mat, ret, tm, tmp;

	for (int i = 0; i < m; i++) {
		int a, b; cin >> a >> b;
		mat[b][a] = true;
	}
	if (T == 0) {
		cout << 1 << "\n";
		return 0;
	}

	auto mul = [&](const array<bitset<size>, size>& a, const array<bitset<size>, size>& b)->array<bitset<size>, size>{
		for (int i = 0; i < size; i++) for (int j = 0; j < size; j++) tm[j][i] = b[i][j];
		for (int i = 0; i < size; i++) for (int j = 0; j < size; j++) tmp[i][j] = (a[i] & tm[j]).any();
		return tmp;
	};
	ret = mat;
	T -= 1;
	while (T > 0) {
		if (T & 1) {
			ret = mul(ret, mat);
		}
		mat = mul(mat, mat);
		T >>= 1;
	}
	int res = 0; for (int i = 0; i < n; i++) res += (int)ret[i][0];
	cout << res << endl;
}