/*
Author: QAQAutomaton
Lang: C++
Code: E.cpp
Mail: lk@qaq-am.com
Blog: https://www.qaq-am.com/
*/
#include<bits/stdc++.h>
#define debug(...) fprintf(stderr,__VA_ARGS__)
#define DEBUG printf("Passing [%s] in LINE %d\n",__FUNCTION__,__LINE__)
#define Debug debug("Passing [%s] in LINE %d\n",__FUNCTION__,__LINE__)
#define all(x) x.begin(),x.end()
#define x first
#define y second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef complex<double> cp;
typedef pair<int,int> pii;
int inf;
const double eps=1e-8;
const double pi=acos(-1.0);
template<class T,class T2>int chkmin(T &a,T2 b){return a>b?a=b,1:0;}
template<class T,class T2>int chkmax(T &a,T2 b){return a<b?a=b,1:0;}
template<class T>T sqr(T a){return a*a;}
template<class T,class T2>T mmin(T a,T2 b){return a<b?a:b;}
template<class T,class T2>T mmax(T a,T2 b){return a>b?a:b;}
template<class T>T aabs(T a){return a<0?-a:a;}
template<class T>int dcmp(T a,T b){return a>b;}
template<int *a>int cmp_a(int x,int y){return a[x]<a[y];}
#define min mmin
#define max mmax
#define abs aabs
struct __INIT__{
	__INIT__(){
		memset(&inf,0x3f,sizeof(inf));
	}
}__INIT___;
namespace io {
	const int SIZE = (1 << 21) + 1;
	char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c, qu[55]; int f, qr;
	// getchar
	#define gc() (iS == iT ? (iT = (iS = ibuf) + fread (ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS ++)) : *iS ++)
	// print the remaining part
	inline void flush () {
		fwrite (obuf, 1, oS - obuf, stdout);
		oS = obuf;
	}
	// putchar
	inline void putc (char x) {
		*oS ++ = x;
		if (oS == oT) flush ();
	}
	template<typename A>
	inline bool read (A &x) {
		for (f = 1, c = gc(); c < '0' || c > '9'; c = gc()) if (c == '-') f = -1;else if(c==EOF)return 0;
		for (x = 0; c <= '9' && c >= '0'; c = gc()) x = x * 10 + (c & 15); x *= f;
		return 1;
	}
	inline bool read (char &x) {
		while((x=gc())==' '||x=='\n' || x=='\r');
		return x!=EOF;
	}
	inline bool read(char *x){
		while((*x=gc())=='\n' || *x==' '||*x=='\r');
		if(*x==EOF)return 0;
		while(!(*x=='\n'||*x==' '||*x=='\r'||*x==EOF))*(++x)=gc();
		*x=0;
		return 1;
	}
	template<typename A,typename ...B>
	inline bool read(A &x,B &...y){
		return read(x)&&read(y...);
	}
	template<typename A>
	inline bool write (A x) {
		if (!x) putc ('0'); if (x < 0) putc ('-'), x = -x;
		while (x) qu[++ qr] = x % 10 + '0',  x /= 10;
		while (qr) putc (qu[qr --]);
		return 0;
	}
	inline bool write (char x) {
		putc(x);
		return 0;
	}
	inline bool write(const char *x){
		while(*x){putc(*x);++x;}
		return 0;
	}
	inline bool write(char *x){
		while(*x){putc(*x);++x;}
		return 0;
	}
	template<typename A,typename ...B>
	inline bool write(A x,B ...y){
		return write(x)||write(y...);
	}
	//no need to call flush at the end manually!
	struct Flusher_ {~Flusher_(){flush();}}io_flusher_;
}
using io :: read;
using io :: putc;
using io :: write;
char s[1000005];
int a[1000005],b[1000005];
int c[3],d[3],at[3];
int c2[3];
char ch[5];
signed main(){
#ifdef QAQAutoMaton 
	freopen("E.in","r",stdin);
	freopen("E.out","w",stdout);
#endif
	read(s+1);
	int n,m=0;
	n=strlen(s+1);
	a[0]=-1;
	for(int i=1;i<=n;++i)if(s[i]-'A'!=a[m])a[++m]=s[i]-'A';
	a[m+1]=-2;
	for(int i=1;i<=m;++i){
		++c2[a[i]];
	}

	d[0]=0;d[1]=1;d[2]=2;
	sort(d,d+3,cmp_a<c2>);
	for(int i=0;i<3;++i)at[d[i]]=i;
	for(int i=0;i<3;++i){
		ch[i]=d[i]+'A';		
	}
	for(int i=0;i<3;++i)c[i]=c2[d[i]];
	for(int i=1;i<=m;++i)b[i]=a[i]=at[a[i]];
	int cn=0;
	for(int i=1;i<=m;++i){
		if(a[i]==2 && (a[i-1]==-1||a[i+1]==-2||((a[i-1]==0)!=(a[i+1]==0)))){
			++cn;
		}
	}
	for(int i=1;i<=m && cn<c[2]-c[1];++i)
		if(a[i]==2 && !a[i-1] && !a[i+1]){
			--c[2];				
			--c[0];
			b[i]=b[i-1]=3;
		}
	for(int i=1;i<=m &&c[2]>c[1];++i){
		if(a[i]==2 && (a[i-1]==-1||a[i+1]==-2||((a[i-1]==0)!=(a[i+1]==0)))){
			--c[2];
			b[i]=3;
		}
	}
	n=0;
	for(int i=1;i<=m;++i)if(b[i]<3)a[++n]=b[i];
	a[n+1]=0;
	for(int i=1,j=1;i<=n;i=j){
		if(a[i]==0){putc(ch[0]);++j;}
		else{
			int m=0;
			while(a[j]){b[++m]=a[j];++j;}
			int lim=i==1||j>n?0:1;
			while(m-2>=lim && c[1]>c[0]){
				--c[1];m-=2;
			}
			for(int k=1;k<=m;++k)putc(ch[b[k]]);
		}
	}
//	for(int i=1;i<=m;++i)if(a[i]<3)putc(ch[a[i]]);
	putc('\n');
	return 0;
}



Measured memory_bytes: 13440