#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MOD 998244353
const int N = 200005;
vector<int> g[N];
int p[N], dep[N];
void dfs(int u, int v = -1){
for(auto c : g[u]){
if(c == v){
continue;
}
dep[c] = dep[u] + 1;
p[c] = u;
dfs(c, u);
}
}
void solve(){
ll n, m, u , v;
cin >> n >> m;
for(int i = 0; i < m; i++){
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
if(m == n - 1){
cout << 2 * n << '\n';
dfs(0);
for(int i = 0 ;i < 2 * n ; i++){
for(int j = 0; j < n; j++){
if(dep[j] % 2 == i % 2){
cout << j << " ";
}
else if(j == 0){
cout << g[j][0] << " ";
}
else{
cout << p[j] << " ";
}
}
cout << '\n';
}
}
else{
cout << n << '\n';
for (int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
cout << (j + (i % 2)) / 2 << ' ';
}
cout << '\n';
}
}
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int tests = 1;
// cin >> tests;
for(int i = 1; i <= tests; i ++)
solve();
}
