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

typedef vector<int> vi;

#define int int64_t

#define loop(i,s,t) for(int i=s;i<t;i++)
#define loopr(i,s,t) for(int i=t-1;i>=s;i--)
#define all(a) a.begin(),a.end()

typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;

int32_t main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    int n, m; cin >> n >> m;
    cout << "YES" << endl;
    cout << 2*m << endl;
    loop(i, 0, m){
        int a, b; cin >> a >> b;
        cout << a << " " << b << " ";
        loop(cand, 1, n+1){
            if(cand != a && cand != b){
                cout << cand << " ";
            }
        }
        cout << endl;
        loopr(cand, 1, n+1){
            if(cand != a && cand != b){
                cout << cand << " ";
            }
        }
        cout << a << " " << b << endl;
    }
    return 0;
}