#include <bits/stdc++.h>
using namespace std;
#define endl '\n'

int main() {
    cin.tie(0)->sync_with_stdio(0);

    int n, m; cin >> n >> m;
    
    cout<<"YES"<<endl;
    cout<<2*m<<endl;

    for (int i = 1; i <= m; i++) {
        int u, v; cin >> u >> v;
        vector<int> a;
        for(int j=1;j<=n;++j)
            if(j!=u&&j!=v)
                a.push_back(j);
        cout<<u<<" "<<v<<" ";
        for(int x:a)
            cout<<x<<" ";
        cout<<endl;
        reverse(a.begin(),a.end());
        for(int x:a)
            cout<<x<<" ";
        cout<<u<<" "<<v<<" ";
        cout<<endl;
    }

    return 0;
}