#include <bits/stdc++.h>
 
using namespace std;

const long long int MOD = 998233453;
vector <vector<long long int>> mul(vector <vector<long long int>> a, vector<vector<long long int>> b)
{
    int n = a.size();
    int m = a[0].size();
    int k = b[0].size();
    vector <vector<long long int>>c(n, vector<long long int>(k,0));

    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < k; j++)
        {
            for (int k = 0; k < m; k++)
            {
                c[i][j] += a[i][k]*b[k][j];
				c[i][j]%=MOD;
            }
        }
    }

    return c;
}

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

	int n,m,x,y;
	long long int t;

	cin >> n >> m >> t;
	vector <vector<long long int>>a(n, vector<long long int>(n,0));
    vector <vector<long long int>>b(n, vector<long long int>(n,0));

	for(int i=0;i<m;i++)
	{
		cin >> x >> y;
		a[y][x] = 1;
	}

	b[0][0] = 1;

    while(t > 0)
    {
        if(t%2==1)
        {
            b = mul(a,b);
        }
        a = mul(a,a);
        t/=2;
    }

	int res = 0;

	for(int i=0;i<n;i++)
	{
		//cout << i << ' ' << b[i][0] << '\n';
		if(b[i][0] > 0) res += 1;
	}	

	cout << res << '\n';

    return 0;
}