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

struct matrix{
    vector<bitset<100>> a;
    matrix():a(100){}
    matrix operator*(const matrix& x) const {
        matrix ans;
        for(int i = 0; i < 100; i++) for(int j = 0; j < 100; j++) if(a[i][j]) ans[i] |= x[j];
        return ans;
    }
    bitset<100>& operator[](int x){ return a[x]; }
    const bitset<100>& operator[](int x) const { return a[x]; }
    matrix pow(uint64_t x) const {
        matrix ans, a = *this;
        for(int i = 0; i < 100; i++) ans[i][i] = 1;
        while(x){
            if(x & 1) ans = ans * a;
            a = a * a;
            x >>= 1;
        }
        return ans;
    }
};
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int N, M;
    long T;
    cin >> N >> M >> T;
    matrix a;
    while(M--){
        int x, y;
        cin >> x >> y;
        a[x][y] = 1;
    }
    cout << a.pow(T)[0].count() << endl;
}