#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
inline int in() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("YES");}else{puts("NO");}
const int MX = 200005;

int n;
vi a;
string cs;
void comp() {
  vi res;
  rep(i,sz(a)) if (a[i] != -1) {
    assert(!sz(res) || res.back() != a[i]);
    res.pb(a[i]);
  }
  swap(res,a);
  n = sz(a);
}
void answer() {
  string ans;
  rep(i,n) ans += cs[a[i]];
  cout<<ans<<endl;
}

int main() {
  {
    string s;
    cin>>s;
    rep(i,sz(s)) {
      int x = s[i]-'A';
      if (sz(a) && a.back() == x) continue;
      a.pb(x);
    }
  }
  int n = sz(a);
  {
    vp c(3);
    rep(i,3) c[i].se = i;
    rep(i,n) c[a[i]].fi++;
    sort(rng(c));
    vi t(3);
    rep(i,3) t[c[i].se] = i;
    rep(i,n) a[i] = t[a[i]];
    rep(i,3) cs += 'A'+c[i].se;
  }
  {
    vi c(3);
    rep(i,n) c[a[i]]++;
    int x = c[2]-c[1];
    int y = c[1]-c[0];
    {
      int pre = -1;
      rep(i,n) {
        if (!x) break;
        if (a[i] == 2) {
          if (i < n-1 && pre == a[i+1]) {
            pre = a[i];
            continue;
          }
          a[i] = -1;
          --x;
        } else pre = a[i];
      }
      comp();
    }
    y += x;
    {
      int pre = -1;
      rep(i,n) {
        if (!y) break;
        if (!i) continue;
        if (a[i-1]+a[i] == 3) {
          if (i != n-1) {
            if (pre == a[i+1]) {
              pre = a[i-1];
              continue;
            }
          }
          a[i-1] = a[i] = -1;
          --y;
        } else if (a[i-1] != -1) pre = a[i-1];
      }
      comp();
    }
    // assert(y == 0);
    {
      int pre = -1;
      rep(i,n) {
        if (!x) break;
        if (!i) continue;
        if (a[i-1]+a[i] == 2) {
          if (i != n-1) {
            if (pre == a[i+1]) {
              pre = a[i-1];
              continue;
            }
          }
          a[i-1] = a[i] = -1;
          --x;
        } else if (a[i-1] != -1) pre = a[i-1];
      }
      comp();
    }
    // assert(x == 0);
  }

  answer();
  return 0;
}






















Measured memory_bytes: 13084