#include <iostream>
#include <vector>
#include <queue>

using namespace std;

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    vector<vector<int>> g(n + 1);
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
    }
    int mod = 1 << k;
    vector<vector<bool>> d(n + 1, vector<bool>(mod, false));
    queue<pair<int, int>> q;
    q.push({1, 0});
    while (!q.empty()) {
        auto [u, r] = q.front();
        q.pop();
        int nr = (r + 1) % mod;
        for (int v : g[u]) {
            if (!d[v][nr]) {
                d[v][nr] = true;
                q.push({v, nr});
            }
        }
    }
    bool f = true;
    int t = mod - 1;
    for (int i = 1; i <= n; ++i) {
        int c = 0;
        for (int r = 0; r < mod; ++r) {
            if (d[i][r]) c |= r;
        }
        if (c != t) {
            f = false;
            break;
        }
    }
    cout << (f ? "Yes" : "No") << endl;
    return 0;
}