using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var x = long.Parse(ReadLine());
        var prev = -1;
        var ans = new List<int[]>();
        var color = new List<char>();
        if (x == 1)
        {
            color.Add('b');
            color.Add('g');
            ans.Add(new int[] { 1, 2 });
        }
        {
            while (x % 4 == 0)
            {
                color.Add('b');
                var br = color.Count;
                if (prev > 0) ans.Add(new int[] { prev, br });
                for (var j = 0; j < 4; ++j)
                {
                    color.Add('g');
                    ans.Add(new int[] { br, color.Count });
                }
                prev = br;
                x /= 4;
            }
        }
        for (var i = 2; i <= 200000; ++i)
        {
            while (x % i == 0)
            {
                color.Add('b');
                var br = color.Count;
                if (prev > 0) ans.Add(new int[] { prev, br });
                for (var j = 0; j < i; ++j)
                {
                    color.Add('g');
                    ans.Add(new int[] { br, color.Count });
                }
                prev = br;
                x /= i;
            }
        }
        if (x > 1 || color.Count > 200000)
        {
            WriteLine(-1);
            return;
        }
        WriteLine(color.Count);
        WriteLine(string.Join("\n", ans.Select(ai => string.Join(" ", ai))));
        WriteLine(string.Join(" ", color));
    }
}