#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int N = 147;
set<int> g[N];
int col[N]; // -1 ne pofarbovano, -2 ne pofarbovano ale yasno
VI yasno;
map<int, int> susids[N];
int n;

bool cmp(int u, int v)
{
	return MP(SZ(susids[u]), SZ(g[u])) > MP(SZ(susids[v]), SZ(g[v]));
}

void solve()
{
	int j = -1;
	FOR (i, 0, n)
	{
		if (col[i] == -1 && (j == -1 || cmp(i, j)))
			j = i;
	}
	if (j == -1)
	{
		RFOR (i, SZ(yasno), 0)
		{
			int v = yasno[i];
			set<int> val;
			for (auto to : g[v])
				val.insert(col[to]);
			FOR (c, 0, 4)
			{
				if (!val.count(c))
				{
					col[v] = c;
					break;
				}
			}
		}
		FOR (i, 0, n)
		{
			cout << i + 1 << ' ' << col[i] + 1 << '\n';
		}
		exit(0);
	}
	FOR (c, 0, 4)
	{
		if (susids[j].count(c))
			continue;
		for (auto to : g[j])
		{
			susids[to][c]++;
		}
		col[j] = c;
		solve();
		col[j] = -1;
		for (auto to : g[j])
		{
			susids[to][c]--;
			if (susids[to][c] == 0)
				susids[to].erase(c);
		}
	}
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	string s;
	while (cin >> s)
	{
		int j = 0;
		while (s[j] != '-')
			j++;
		int u = stoi(s.substr(0, j));
		int v = stoi(s.substr(j + 1, SZ(s) - j - 1));
		u--, v--;
		g[u].insert(v);
		g[v].insert(u);
	}
	fill(col, col + n, -1);
	while (true)
	{
		int j = -1;
		FOR (i, 0, n)
		{
			if (col[i] == -1 && SZ(g[i]) <= 3)
			{
				j = i;
				break;
			}
		}
		if (j == -1)
			break;
		col[j] = -2;
		yasno.PB(j);
		for (auto v : g[j])
			g[v].erase(j);
	}
	solve();
	
	
	return 0;
}