using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Practice
{
	using Pair = Tuple<long, long>;
	class Program
	{
		static void Main(string[] args)
		{
			Solve();
		}
		private const int MOD = 10007;// 1000000007;

		private static long[] a;
		private static long[] b;
		private static long[] s;// 作成数
		static void Solve()
		{
			var s = Console.ReadLine();
			int[] totals = new int[3];
			for(int i=0;i<s.Length;++i)
			{
				totals[s[i] - 'a']++;
			}
			var ans = IsValid(totals) ? "YES" : "NO";
			Console.WriteLine(ans);
			
		}
		private static bool IsValid(int[] totals)
		{
			if( totals[0] == totals[1] && totals[1] == totals[2]) { return true; }
			for(int i=0;i<3;++i)
			{
				if(totals[i] == totals[(i + 1) % 3] && totals[(i + 2) % 3] == totals[i] + 1) { return true; }
				if(totals[i] == totals[(i + 1) % 3] && totals[(i + 2) % 3] == totals[i] - 1) { return true; }

			}
			return false;
		}

		private class Comparer : IComparer<int>
		{
			public int Compare(int x , int y)
			{
				long cx = CalcCost(x);
				long cy = CalcCost(y);
				return cx.CompareTo(cy);
			}
		}


		private static long CalcCost(int idx)
		{
			
			return a[idx] + s[idx] * b[idx];
		}
		public class PriorityQueue<T> where T : IComparable
		{
			private IComparer<T> _comparer = null;
			private int _type = 0;

			private T[] _heap;
			private int _sz = 0;

			private int _count = 0;

			/// <summary>
			/// Priority Queue with custom comparer
			/// </summary>
			public PriorityQueue(int maxSize, IComparer<T> comparer)
			{
				_heap = new T[maxSize];
				_comparer = comparer;
			}

			/// <summary>
			/// Priority queue
			/// </summary>
			/// <param name="maxSize">max size</param>
			/// <param name="type">0: asc, 1:desc</param>
			public PriorityQueue(int maxSize, int type = 0)
			{
				_heap = new T[maxSize];
				_type = type;
			}

			private int Compare(T x, T y)
			{
				if(_comparer != null) return _comparer.Compare(x, y);
				return _type == 0 ? x.CompareTo(y) : y.CompareTo(x);
			}

			public void Push(T x)
			{
				_count++;

				//node number
				var i = _sz++;

				while(i > 0)
				{
					//parent node number
					var p = (i - 1) / 2;

					if(Compare(_heap[p], x) <= 0) break;

					_heap[i] = _heap[p];
					i = p;
				}

				_heap[i] = x;
			}

			public T Pop()
			{
				_count--;

				T ret = _heap[0];
				T x = _heap[--_sz];

				int i = 0;
				while(i * 2 + 1 < _sz)
				{
					//children
					int a = i * 2 + 1;
					int b = i * 2 + 2;

					if(b < _sz && Compare(_heap[b], _heap[a]) < 0) a = b;

					if(Compare(_heap[a], x) >= 0) break;

					_heap[i] = _heap[a];
					i = a;
				}

				_heap[i] = x;

				return ret;
			}

			public int Count()
			{
				return _count;
			}

			public T Peek()
			{
				return _heap[0];
			}

			public bool Contains(T x)
			{
				for(int i = 0; i < _sz; i++) if(x.Equals(_heap[i])) return true;
				return false;
			}

			public void Clear()
			{
				while(this.Count() > 0) this.Pop();
			}

			public IEnumerator<T> GetEnumerator()
			{
				var ret = new List<T>();

				while(this.Count() > 0)
				{
					ret.Add(this.Pop());
				}

				foreach(var r in ret)
				{
					this.Push(r);
					yield return r;
				}
			}

			public T[] ToArray()
			{
				T[] array = new T[_sz];
				int i = 0;

				foreach(var r in this)
				{
					array[i++] = r;
				}

				return array;
			}
		}

		#region よく使う便利関数a
		private static bool isPrime(long x)
		{
			if(x == 2) { return true; }
			if(x < 2 || x % 2 == 0) { return false; }
			long i = 3;
			while(i * i <= x)
			{
				if(x % i == 0) { return false; }
				i = i + 2;
			}
			return true;
		}
		private static long lcm(long x, long y)
		{
			return x / gcd(x, y) * y;
		}
		private static long gcd(long x, long y)
		{
			return y > 0 ? gcd(y, x % y) : x;
		}
		private static long pow(long x, long n)
		{
			if(n == 0) { return 1; }
			long res = pow(x * x % MOD, n / 2);
			if(n % 2 == 1)
			{
				res = res * x % MOD;
			}
			return res;
		}
		private static int ReadAndParseInt()
		{
			return int.Parse(Console.ReadLine());
		}
		private static int[] ReadAndParseIntArr()
		{
			return Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
		}
		private static long ReadAndParseLong()
		{
			return long.Parse(Console.ReadLine());
		}
		private static long[] ReadAndParseLongArr()
		{
			return Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);
		}

		/// <summary>
		/// 指定した値以上の先頭のインデクスを返す
		/// </summary>
		/// <typeparam name="T">比較する値の型</typeparam>
		/// <param name="arr">対象の配列（※ソート済みであること）</param>
		/// <param name="start">開始インデクス [inclusive]</param>
		/// <param name="end">終了インデクス [exclusive]</param>
		/// <param name="value">検索する値</param>
		/// <param name="comparer">比較関数(インターフェイス)</param>
		/// <returns>指定した値以上の先頭のインデクス</returns>
		public static int LowerBound<T>(IReadOnlyList<T> arr, int start, int end, T value, IComparer<T> comparer)
		{
			int low = start;
			int high = end;
			int mid;
			while(low < high)
			{
				mid = ((high - low) >> 1) + low;
				if(comparer.Compare(arr[mid], value) < 0)
					low = mid + 1;
				else
					high = mid;
			}
			return low;
		}

		//引数省略のオーバーロード
		public static int LowerBound<T>(IReadOnlyList<T> arr, T value) where T : IComparable
		{
			return LowerBound(arr, 0, arr.Count, value, Comparer<T>.Default);
		}

		/// <summary>
		/// 指定した値より大きい先頭のインデクスを返す
		/// </summary>
		/// <typeparam name="T">比較する値の型</typeparam>
		/// <param name="arr">対象の配列（※ソート済みであること）</param>
		/// <param name="start">開始インデクス [inclusive]</param>
		/// <param name="end">終了インデクス [exclusive]</param>
		/// <param name="value">検索する値</param>
		/// <param name="comparer">比較関数(インターフェイス)</param>
		/// <returns>指定した値より大きい先頭のインデクス</returns>
		public static int UpperBound<T>(IReadOnlyList<T> arr, int start, int end, T value, IComparer<T> comparer)
		{
			int low = start;
			int high = end;
			int mid;
			while(low < high)
			{
				mid = ((high - low) >> 1) + low;
				if(comparer.Compare(arr[mid], value) <= 0)
					low = mid + 1;
				else
					high = mid;
			}
			return low;
		}

		//引数省略のオーバーロード
		public static int UpperBound<T>(IReadOnlyList<T> arr, T value)
		{
			return UpperBound(arr, 0, arr.Count, value, Comparer<T>.Default);
		}
		#endregion
	}
	public class DisjointSet
	{
		private int[] rank;
		private int[] p;
		private int[] size;
		public DisjointSet(int n)
		{
			rank = new int[n];
			p = new int[n];
			size = new int[n];
			for(int i = 0; i < n; ++i)
			{
				MakeSet(i);
			}
		}
		public void MakeSet(int x)
		{
			p[x] = x;
			rank[x] = 0;
			size[x] = 1;
		}
		public bool IsSame(int x, int y)
		{
			return FindSet(x) == FindSet(y);
		}
		public void Unite(int x, int y)
		{
			Link(FindSet(x), FindSet(y));
		}
		public void Link(int x, int y)
		{
			if(rank[x] > rank[y])
			{
				p[y] = x;
				size[x] += size[y];
				size[y] = 0;
			}
			else
			{
				p[x] = y;
				size[y] += size[x];
				size[x] = 0;
				if(rank[x] == rank[y])
				{
					rank[y]++;
				}
			}
		}
		public int FindSet(int x)
		{
			if(x != p[x])
			{
				p[x] = FindSet(p[x]);
			}
			return p[x];
		}
		public int Size(int x)
		{
			int root = FindSet(x);
			return size[root];
		}
	}
}


Measured memory_bytes: 13140