#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
int main() {
	long long mod = 1000000007;
	int m_size;
	cin >> m_size;
	int m;
	cin >> m;
	vector<vector<long long>> mat(220);
	long long y;
	cin >> y;
	if (y == 0) {
		cout << 1 << endl;
		return 0;
	}
	vector<vector<long long>> ans(220);
	for (int i = 0; i < m_size; i++) {
		for (int j = 0; j < m_size; j++) {
			mat[i].emplace_back(0);
			ans[i].emplace_back(0);
		}
	}
	for (int i = 0; i < m; i++) {
		int a, b;
		cin >> a >> b;
		mat[b][a] = 1;
		ans[b][a] = 1;
	}
	y--;
	while (y > 0) {
		if ((y & 1) == 1) {
			vector<vector<long long>> ans_mem(220);
			for (int i = 0; i < m_size; i++) {
				for (int j = 0; j < m_size; j++) {
					ans_mem[i].emplace_back(0);
				}
			}
			for (int i = 0; i < m_size; i++) {
				for (int j = 0; j < m_size; j++) {
					for (int k = 0; k < m_size; k++) {
						ans_mem[i][j] += ans[i][k] * mat[k][j];
					}
					if (ans_mem[i][j] > 0) {
						ans_mem[i][j] = 1;
					}
				}
			}
			ans = ans_mem;
		}
		vector<vector<long long>> mat_mem(220);
		for (int i = 0; i < m_size; i++) {
			for (int j = 0; j < m_size; j++) {
				mat_mem[i].emplace_back(0);
			}
		}
		for (int i = 0; i < m_size; i++) {
			for (int j = 0; j < m_size; j++) {
				for (int k = 0; k < m_size; k++) {
					mat_mem[i][j] += mat[i][k] * mat[k][j];
				}
				if (mat_mem[i][j] > 0) {
					mat_mem[i][j] = 1;
				}
			}
		}
		mat = mat_mem;
		y >>= 1;
	}
	int co = 0;
	for (int i = 0; i < m_size; i++) {
		if (ans[i][0] != 0) {
			co++;
		}
	}
	cout << co << endl;
}