#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const double eps = 1e-10;
const int MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll<<50;

template<typename T>
void printv(const vector<T>& s) {
  for(int i=0;i<(int)(s.size());++i) {
    cout << s[i];
    if(i == (int)(s.size())-1) cout << endl;
    else cout << " ";
  }
}

int main () {
  cin.tie(0);
  cout << fixed << setprecision(10);

  string s; cin >> s;
  int n = s.size();

  while(n > 3) {
    string tmp;
    for(int i=0;i<n;++i) {
      int sz = tmp.size();
      if(sz >= 2 && tmp[sz-2] == 'A' && tmp[sz-1] == 'B' && s[i] == 'C') {
        tmp.pop_back();
        tmp.pop_back();
      } else {
        tmp.push_back(s[i]);
      }
    }

    // cout << tmp << endl;

    bool a = true, b = true, c = true;
    int sz = tmp.size();
    for(int i=0;i<sz;++i) {
      if(tmp[i] == 'A') {
        a = false;
      } else if(tmp[i] == 'B') {
        b = false;
      } else {
        c = false;
      }
    }

    if(!((a && !b && !c) || (!a && b && !c) || (!a && !b && c))) {
      cout << "No" << endl;
      return 0;
    }

    tmp.clear();
    // cout << s << endl;

    int cnt = 0;
    for(int i=0;i<n;++i) {
      int sz = tmp.size();
      if(cnt <= 0 && sz >= 2 && tmp[sz-2] == 'A' && tmp[sz-1] == 'B' && s[i] == 'C') {
        tmp.pop_back();
        tmp.pop_back();
        if(a) {
          tmp.push_back('A');
        } else if(b) {
          tmp.push_back('B');
        } else {
          tmp.push_back('C');
        }
        cnt = 2;
      } else {
        tmp.push_back(s[i]);
        cnt--;
      }
      //cout << tmp << endl;
    }

    s = tmp;
    n = s.size();
    // cout << s << endl;;
  }

  if(s == "ABC") {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}

