L2

#include "pch.h"
#include <iostream>
#include <string>
using namespace std;

int main()
{
    char c;
    string st;
    getline(cin, st);
    int s = 0;
    for (int i = 0, l = st.length(); i < l && s != 3; i++) {
        c = st[i];
        switch (s) {
        case 0:
            if (c == 'A' || c == 'C')
                s = 0;
            else if (c == 'B')
                s = 1;
            else
                s = 3;
            break;
        case 1:
            if (c == 'C' || c=='A')
                s = 2;
            else
                s = 3;
            break;
        case 2:
            if (c == 'A' || c == 'B' || c == 'C')
                s = 3;
            break;
        }
    }
    if (s == 2) cout << "Yes";
    else if (s == 3) cout << "No";

    return 0;
}