#include <bits/stdc++.h>
#define be(v) (v).begin(),(v).end()
#define pb(q) push_back(q)
typedef long long ll;
using namespace std;
const ll mod=1000000007, INF=(1LL<<60);
#define doublecout(a) cout<<fixed<<setprecision(10)<<a<<endl;

int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);
    ll n, m, t, a, b;
    cin >> n >> m >> t;
    for(int i=0;i<m;i++){
        cin >> a >> b;
    }
    cout << -1 << endl;
    return 0;
}