#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;

int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  
  string s;
  cin >> s;
  queue<string> que;
  que.emplace(s);
  bool yes = false;
  while (!que.empty()) {
    string p = que.front(); que.pop();
    if (p == "ABC") {
      yes = true;
      break;
    }
    if ((int)p.size() <= 3) continue;
    int pz = p.size(), used[3] = {};
    bool no_abc = true;
    for (int i = 0; i < pz; i++) {
      if (i + 3 <= pz && p.substr(i, 3) == "ABC") {
        no_abc = false;
        if (i + 3 == pz) break;
        i += 2;
      } else {
        used[p[i] - 'A']++;
      }
    }
    if (no_abc) continue;
    bool all_used = true;
    for (int $ = 0; $ < 3; $++) {
      all_used &= used[$];
    }
    if (all_used) continue;
    for (int $ = 0; $ < 3; $++) {
      if (used[$]) continue;
      string t;
      for (int i = 0; i < pz; i++) {
        if (i + 3 <= pz && p.substr(i, 3) == "ABC") {
          t += char($ + 'A');
          if (i + 3 == pz) break;
          i += 2;
        } else {
          t += p[i];
        }
      }
      que.emplace(t);
    }
  }
    cout << (yes ? "Yes" : "No") << endl;

  return 0;
}
