#include <iostream>
#include <set>
#include <vector>
#include <algorithm>

#define foreach(T,p,c) for(T p = (c).begin(); p != (c).end(); p++)

using namespace std;

int main(void)
{
	int code[7500], last[7500];
	vector<int> adj[7500];

	int n = 0, m;

	while(cin >> m) code[n++] = m - 1;

	set<int> A;
	for(int i = 0; i <= n; i++) A.insert(i);

	for(int i = n - 1; i >= 0; i--) {
		if(A.find(code[i]) != A.end()) {
			last[i] = code[i];
			A.erase(code[i]);
		}
		else {
			last[i] = -1;
		}
	}

	for(int i = 0; i < n; i++) {
		m = *(A.begin());
		A.erase(m);
		adj[code[i]].push_back(m);
		adj[m].push_back(code[i]);
		if(last[i] >= 0) A.insert(last[i]);
	}

	for(int i = 0; i <= n; i++) {
		sort(adj[i].begin(), adj[i].end());
		cout << (i + 1) << ":";
		foreach(vector<int>::iterator, p, adj[i]) cout << " " << (*p + 1);
		cout << endl;
	}

	return 0;
}