#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using ll=long long;
using vi=vector<int>;
using pii=pair<int,int>;
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define ITR(i,b,e) for(auto i=(b);i!=(e);++i)
#define FORE(x,c) for(auto &x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define OUTOFRANGE(y,x,h,w) ((y)<0||(x)<0||(y)>=(h)||(x)>=(w))
#define dump(...)
const signed INF_=1001001001; const long long INF=1001001001001001001LL;
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
template<class T> ostream& operator<<(ostream &os,const vector<T> &v) {
    ITR(i,begin(v),end(v))os<<*i<<(i==end(v)-1?"":" ");return os;}
template<class T> istream& operator>>(istream &is,vector<T> &v) {
    ITR(i,begin(v),end(v)) is>>*i;return is;}
template<class T,class U> istream& operator>>(istream &is, pair<T,U> &p) {
    is>>p.first>>p.second;return is;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}return 0;}
template<class T> using heap=priority_queue<T,vector<T>,greater<T>>;
struct{template<class T> operator T(){T x;cin>>x;return x;}} IN;
struct before_main_function {
    before_main_function() {
        #define endl "\n"
        cin.tie(0);ios::sync_with_stdio(false);
        cout<<setprecision(15)<<fixed;
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

signed main() {
    string s;
    cin >> s;
    if (s == "ABC") {
        cout << "Yes" << endl;
        return 0;
    }

    while (1) {
        string t = "";
        map<char, int> cnt;
        bool f = false;
        REP(i, SZ(s)) {
            if (s.substr(i, 3) == "ABC") {
                t += "#";
                i+=2;
                f = true;
            } else {
                t += s[i];
                cnt[s[i]]++;
            }
        }
        if (!f) break;
        
        char x = '#';
        if (cnt['A'] == 0 && cnt['B'] > 0 && cnt['C'] > 0) {
            x = 'A';
        } else if (cnt['A'] > 0 && cnt['B'] == 0 && cnt['C'] > 0) {
            x = 'B';
        } else if (cnt['A'] > 0 && cnt['B'] > 0 && cnt['C'] == 0) {
            x = 'C';
        }

        if (x == '#') {
            cout << "No" << endl;
            return 0;
        }
        REP(i, SZ(t)) {
            if (t[i] == '#') t[i] = x;
        }
        s = t;
        if (s == "ABC") {
            cout << "Yes" << endl;
            return 0;
        }
    }
    cout << "No" << endl;
    return 0;
}


