#include <cstdio>
#include <algorithm>
#include <iostream>
#include <cmath>
#include <cstring>
#include <iomanip>
#include <map>
#include <string>
#include <cstdlib>
#include <queue>
#include <stack>
#include <utility>
#define LL long long
#define eps 1e-7
using namespace std;
int main()
{
    ios::sync_with_stdio(false);
    //freopen("D:/test.in", "r, stdin);
    //freopen("D:/test.out", "w", stdout);
    string s;
    while(cin >> s)
    {
        map<char,int>p;
        int ok = 0,te = 1;
        int len = s.length();
        for(int i = 0;i < len;i++)
        {
            p[s[i]]++;
        }
        if(p.size() != 3)
        {
            cout << "NO" << endl;
            continue;
        }
        for(int i = 0;i < len;i++)
        {
            if(s[i] == s[i + 1])
            {
                te++;
            }
            else
            {
                if(te != len / 3)
                {
                    cout << "NO" << endl;
                    ok = 1;
                    break;
                }
                else
                {
                    te = 1;
                }
            }
        }
        if(!ok)
        {
            cout << "YES" << endl;
        }
    }
return 0;
}