#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y));
#define chmax(x,y) x = max((x),(y));
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;

int G[105][105];
int doubling[66][105][105];// 1<<i回でj->kに行ける

int main(){
    int n,m;
    ll t;
    cin >> n >> m >> t;
    rep(i,m){
        int a,b;
        cin >> a >> b;
        doubling[0][a][b] = 1;
    }
    for(int i=0;i<65;i++){
        rep(j,n){
            rep(k,n){
                // doubling[i+1][j][k]
                rep(l,n){
                    if(doubling[i][j][l] == 1 && doubling[i][l][k] == 1){
                        doubling[i+1][j][k] = 1;
                        break;
                    }
                }
            }
        }
    }
    vector<int> been(n,0);
    been[0] = 1;
    int c = 0;
    while(t > 0){
        if(t&1){
            vector<int> nxt(n,0);
            rep(i,n){
                if(been[i]==1){
                    rep(j,n){
                        if(doubling[c][i][j] == 1){
                            nxt[j] = 1;
                        }
                    }
                }
            }
            swap(been,nxt);
        }
        t >>= 1;
        ++c;
    }
    int sum = 0;
    rep(i,n) sum += (been[i]==1);
    cout << sum << endl;
    return 0;
}