#include<stdio.h>
#include<assert.h>

#include<vector>
#include<algorithm>

using namespace std;

vector<int> graph[100005];
vector<vector<int> > ans;
vector<int> stack;
int n,m,vis[100005];

void read(){
	assert(freopen("biconex.in","r",stdin));
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= m; ++i){
		int x, y;
		scanf("%d%d",&x,&y);
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
}

void dfs(int x){
	vis[x] = 0;
	stack.push_back(x);
	for(int i = 0; i < graph[x].size(); ++i)
		if(vis[graph[x][i]]){
			int p = graph[x][i];
			vector <int> an;
			int t = stack.size() - 1;
			do{
				an.push_back(stack[t]);
				--t;
			}while(stack[t] != p);
			an.push_back(p);
			ans.push_back(an);
		}
		else
			dfs(graph[x][i]);
	stack.pop_back();
}

void solve(){
	for(int i = 1; i <= n; ++i)
		if(!vis[i])
			dfs(i);
}

void write(){
	assert(freopen("biconex.out", "w",stdout);
	printf("%d\n",ans.size());
	for(int i = 0; i < ans.size(); ++i){
		for(int j = 0; j < ans[i].size(); ++j)
			printf("%d ",ans[i][j]);
		printf("\n");
	}
}

int main(){
	read();
	solve();
	write();
}