#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
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 (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n,m,t;cin >> n >> m >> t;
    int logt=1;
    while((1LL<<logt)<t) logt++;
    vector d(logt+1,vector(n,vector(n,false)));
    REP(i,m){
        int a,b;cin >> a >> b;
        d[0][a][b]=true;
    }
    REP(i,logt){
        REP(j,n){
            REP(l,n){
                if(d[i][j][l]){
                    REP(s,n){
                        if(d[i][l][s]) d[i+1][j][s]=true;
                    }
                }
            }
        }
    }
    vector<bool> now(n);
    now[0]=true;
    int cnt=0;
    while(t){
        if(t&1){
            vector<bool> tmp(n);
            REP(i,n){
                if(now[i]){
                    REP(j,n){
                        if(d[cnt][i][j]) tmp[j]=true;
                    }
                }
            }
            swap(now,tmp);
        }
        t>>=1;
        cnt++;
    }
    int ans=0;
    REP(i,n) if(now[i]) ans++;
    cout << ans << endl;
}