#include<bits/stdc++.h>
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define pii pair<ll,ll>
#define rep(i,a,b) for(ll i=(a);i<=(b);++i)
#define per(i,a,b) for(ll i=(a);i>=(b);--i)
using namespace std;
bool Mbe;
ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
void write(ll x){
    if(x<0)putchar('-'),x=-x;
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
const ll N=109;
ll n,m,U[N*N],V[N*N],dep[N],ft[N],id[N],rt;
vector<vector<ll> >res;
vector<ll>to[N];
ll find(ll x){
    return id[x]==x?x:id[x]=find(id[x]);
}
void merge(ll x,ll y){
    x=find(x),y=find(y);
    if(x^y)id[x]=y;
}
void dfs(ll x,ll fa){
    for(ll y:to[x]){
        if(y==fa)continue;
        ft[y]=x,dep[y]=dep[x]+1;
        dfs(y,x);
    }
}
bool Med;
int main(){
    // freopen("meet.in","r",stdin);
    // freopen("meet.out","w",stdout);
    cerr<<fabs(&Med-&Mbe)/1048576.0<<"MB\n";
    n=read(),m=read();
    rep(i,1,m)U[i]=read(),V[i]=read(),to[U[i]].push_back(V[i]),to[V[i]].push_back(U[i]);
    if(m==n*(n-1)/2){
        rep(i,0,2*n-1){
            vector<ll>v(n,0);
            ll c=0;
            if(i&1){
                ll j=0;
                for(;j+1<n;j+=2)v[j]=v[j+1]=c,c++;
                while(j<n)v[j]=c,j++,c++;
            }
            else{
                ll j=1;
                v[0]=0,c++;
                for(;j+1<n;j+=2)v[j]=v[j+1]=c,c++;
                while(j<n)v[j]=c,j++,c++;
            }
            res.push_back(v);
        }
        write(res.size()),putchar('\n');
        for(vector<ll>v:res){
            for(ll x:v)write(x),putchar(' ');
            putchar('\n');
        }
        return 0;
    }
    if(m==n-1){
        dfs(0,-1);
        rep(i,0,2*n-1){
            vector<ll>v(n,0);
            iota(id,id+n,0ll);
            v[0]=to[0][0];
            rep(j,0,n-1){
                if((dep[j]&1)==(i&1))v[j]=j;
                else if(j)v[j]=ft[j];
            }
            res.push_back(v);
        }
        write(res.size()),putchar('\n');
        for(vector<ll>v:res){
            for(ll x:v)write(x),putchar(' ');
            putchar('\n');
        }
        return 0;
    }

    cerr<<"\n"<<clock()*1.0/CLOCKS_PER_SEC*1000<<"ms\n";
    return 0;
}