using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;



class Myon
{
    public Myon() { }
    public static int Main()
    {
        cin = new Scanner();
        new Myon().calc();
        return 0;
    }

    static Scanner cin;


    int N;
    int[] num;
    int[] preP;
    int[] nextP;
    bool[] used;

    int[] cnt;

    Queue<int>[,] q;

    void calc()
    {
        string S = cin.next();
        List<int> numL = new List<int>();
        char pre = 'D';
        for (int i = 0; i < S.Length; i++)
        {
            if (S[i] == pre) continue;
            pre = S[i];
            numL.Add((int)(S[i] - 'A'));
        }

        N = numL.Count;
        num = numL.ToArray();

        q = new Queue<int>[3, 3];
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                q[i, j] = new Queue<int>();
            }
        }

        preP = new int[N];
        nextP = new int[N];

        cnt = new int[3];
        used = new bool[N];

        for (int i = 0; i < N; i++)
        {
            preP[i] = i - 1;
            nextP[i] = i + 1;
            SetQ(i);

            cnt[num[i]]++;
        }

        StringBuilder sb = new StringBuilder();

        while (cnt[0] != cnt[1] || cnt[0] != cnt[2])
        {
            int[] rank = new int[3] { 0, 1, 2 };
            if (cnt[rank[0]] < cnt[rank[1]]) swap(ref rank[0], ref rank[1]);
            if (cnt[rank[1]] < cnt[rank[2]]) swap(ref rank[1], ref rank[2]);
            if (cnt[rank[0]] < cnt[rank[1]]) swap(ref rank[0], ref rank[1]);

            //Console.ReadLine();
            //Console.WriteLine(cnt[0] + " " + cnt[1] + " " + cnt[2]);

            if (cnt[rank[2]] < cnt[rank[1]])
            {
                //01, 00, 02
                bool ok = false;
                int a, b;
                a = rank[0]; b = rank[1];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[0];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[2];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
            }
            else if (cnt[rank[0]] > cnt[rank[1]])
            {
                //00, 01, 02

                bool ok = false;
                int a, b;
                a = rank[0]; b = rank[0];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[1];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[2];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
            }
            else
            {
                //01, 00, 02

                bool ok = false;
                int a, b;
                a = rank[0]; b = rank[1];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[0];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
                a = rank[0]; b = rank[2];
                while (!ok && q[a, b].Count > 0) { if (CheckAndDelete(q[a, b].Dequeue(), a, b)) ok = true; }
            }
        }

        int start = N;
        for (int i = 0; i < N; i++)
        {
            if(!used[i])
            {
                start = i;
                break;
            }
        }
        while(start != N)
        {
            sb.Append((char)(num[start] + 'A'));
            start = nextP[start];
        }


        Console.WriteLine(sb.ToString());
    }

    bool CheckAndDelete(int p, int a, int b)
    {
        if (used[p]) return false;
        if (num[p] != a) return false;
        int g = getQ(p);
        if (g != b) return false;

        int next = nextP[p];

        Delete(p);
        if (a != b) Delete(next);

        return true;
    }

    void Delete(int p)
    {
        int pre = preP[p];
        int next = nextP[p];
        if(pre != -1)
        {
            nextP[pre] = next;
            SetQ(pre);
        }
        if(next != N)
        {
            preP[next] = pre;
            SetQ(next);
        }

        used[p] = true;
        cnt[num[p]]--;
        return; 
    }

    void SetQ(int i)
    {
        int p = getQ(i);
        q[num[i], p].Enqueue(i);
    }

    int getQ(int i)
    {
        int l, r;
        if (preP[i] == -1) l = -1;
        else l = num[preP[i]];
        if (nextP[i] == N) r = -2;
        else r = num[nextP[i]];

        if (l == r) return l;
        else return num[i];
    }


    //swap
    void swap<T>(ref T a, ref T b)
    {
        T c = a;
        a = b;
        b = c;
    } 


}



class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        if (s.Length == 0) return next();
        i = 0;
        return s[i++];
    }

    public int nextInt()
    {
        return int.Parse(next());
    }
    public int[] ArrayInt(int N, int add = 0)
    {
        int[] Array = new int[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextInt() + add;
        }
        return Array;
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public long[] ArrayLong(int N, long add = 0)
    {
        long[] Array = new long[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextLong() + add;
        }
        return Array;
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }


    public double[] ArrayDouble(int N, double add = 0)
    {
        double[] Array = new double[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextDouble() + add;
        }
        return Array;
    }
}


Measured memory_bytes: 55180