// 7:30
#include <iostream>
#include <cstring>
#include <cmath>
#include <string>
#include <algorithm>
#include <utility>
#include <vector>
#include <set>
#include <map>
#include <deque>
#include <tuple>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll,ll>;
using tll = tuple<ll,ll,ll>;
#define pb push_back
#define for1(i,n) for (ll i=0;i<(n);(i)++)
#define for2(i,m,n) for (ll i=(m);(i)<(n);(i)++)
#define for3(i,m,n,d) for (ll i=(m);(i)<(n);(i)+=(d))
#define INF (1LL << 60)
#define DEBUG 0
#if DEBUG
    #define dump(v1) dump_1(#v1, v1)
    #define dump2(v1,v2) dump_2(#v1, v1, #v2, v2)
    #define dump3(v1,v2,v3) dump_3(#v1, v1, #v2, v2, #v3, v3)
#else
    #define dump(v1)
    #define dump2(v1,v2)
    #define dump3(v1,v2,v3)
#endif
#if DEBUG
template <typename T>
void dump_1(const string& n1, const T& v1)
{
    cerr << n1 << ": " << v1 << endl;
}
template <typename T1, typename T2>
void dump_2(const string& n1, const T1& v1, const string& n2, const T2& v2)
{
    cerr << n1 << ": " << v1 << "  " << n2 << ": " << v2 << endl;
}
template <typename T1, typename T2, typename T3>
void dump_3(const string& n1, const T1& v1, const string& n2, const T2& v2, const string& n3, const T3& v3)
{
    cerr << n1 << ": " << v1 << "  " << n2 << ": " << v2 << "  " << n3 << ": " << v3 << endl;
}
template <typename T1,typename T2>
ostream& operator << (ostream& os, const pair<T1,T2>& v)
{
    os << "(" << v.first << ", " << v.second << ")";
    return os;
}
template <typename T1,typename T2, typename T3>
ostream& operator << (ostream& os, const tuple<T1,T2,T3>& v)
{
    os << "(" << get<0>(v) << ", " << get<1>(v) << ", " << get<2>(v) << ")";
    return os;
}
template <typename T>
ostream& operator << (ostream& os, const vector<T>& v)
{
    os << "[";
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ", ";
        }
        os << *it;
    }
    os << "]";
    return os;
}
template <typename T>
ostream& operator << (ostream& os, const set<T>& v)
{
    os << "{";
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ", ";
        }
        os << *it;
    }
    os << "}";
    return os;
}
template <typename T1, typename T2>
ostream& operator << (ostream& os, const map<T1,T2>& v)
{
    os << "{";
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ", ";
        }
        os << it->first << ":" << it->second;
    }
    os << "}";
    return os;
}
#endif // DEBUG
template <typename T>
void print(const T& v)
{
    cout << v << endl;
}
//---------------------------------------------------------

void solve()
{
    vll cnt(3,0);
    string S;
    cin >> S;
    // aa x
    // aba x
    // abb x
    // abcc x
    // abcb x
    // abcab
    for (char c:S) {
        cnt[c - 'a']++;
    }
    ll len = S.length();
    if (len % 3 == 0) {
        if (cnt[0] == cnt[1] && cnt[0] == cnt[2]) {
            print("YES");
        } else {
            print("NO");
        }
        return;
    }
    sort(cnt.begin(), cnt.end());
    if (len % 3 == 1) {
        if (cnt[0] == cnt[1] && cnt[0] == cnt[2]-1) {
            print("YES");
        } else {
            print("NO");
        }
        return;
    }
    if (len % 3 == 2) {
        if (cnt[0] == cnt[1]-1 && cnt[0] == cnt[2]-1) {
            print("YES");
        } else {
            print("NO");
        }
        return;
    }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    solve();
}


Measured memory_bytes: 512