#include<bits/stdc++.h>
using namespace std;
using LL=long long;
using ULL=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

struct matrix{
  int A[100][100]={};
};

void matrix_multiply(const matrix& l,const matrix& r,matrix& dest){
  static matrix buf;
  rep(i,100) rep(j,100){ buf.A[i][j]=0; rep(k,100) buf.A[i][j]|=(l.A[i][k]&r.A[k][j]); }
  dest = buf;
}

int N,V;
ULL T;
matrix G;
matrix P[64];
matrix dp;

int main(){
  scanf("%d%d%llu",&N,&V,&T);
  rep(i,V){ int u,v; scanf("%d%d",&u,&v); G.A[u][v]=1; }
  P[0]=G;
  rep(i,63) matrix_multiply(P[i],P[i],P[i+1]);
  dp.A[0][0]=1;
  rep(i,64) if(T&(1ull<<i)) matrix_multiply(dp,P[i],dp);
  int ans=0; rep(i,N) ans+=dp.A[0][i];
  printf("%d\n",ans);
  return 0;
}