One day Anna got the following task at school: to arrange several numbers in a circle so that any two neighboring numbers differs exactly by 1. Anna was given several numbers and arranged them in a circle to fulfill the task. Then she wanted to check if she had arranged the numbers correctly, but at this point her younger sister Maria came and shuffled all numbers. Anna got sick with anger but what's done is done and the results of her work had been destroyed. But please tell Anna: could she have hypothetically completed the task using all those given numbers?

Input

The first line contains an integer n — how many numbers Anna had (3 ≤ n ≤ 105). The next line contains those numbers, separated by a space. All numbers are integers and belong to the range from 1 to 109.

Output

Print the single line "YES" (without the quotes), if Anna could have completed the task correctly using all those numbers (using all of them is necessary). If Anna couldn't have fulfilled the task, no matter how hard she would try, print "NO" (without the quotes).

Examples

Input

4
1 2 3 2


Output

YES


Input

6
1 1 2 2 2 3


Output

YES


Input

6
2 4 1 1 2 2


Output

NO
#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:36777216")
#pragma GCC optimize("O2")
template <class T>
inline void RD(T &);
template <class T>
inline void OT(const T &);
inline int RD() {
  int x;
  RD(x);
  return x;
}
template <class T>
inline T &_RD(T &x) {
  RD(x);
  return x;
}
inline void RC(char &c) { scanf(" %c", &c); }
inline void RS(char *s) { scanf("%s", s); }
template <class T0, class T1>
inline void RD(T0 &x0, T1 &x1) {
  RD(x0), RD(x1);
}
template <class T0, class T1, class T2>
inline void RD(T0 &x0, T1 &x1, T2 &x2) {
  RD(x0), RD(x1), RD(x2);
}
template <class T0, class T1, class T2, class T3>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3) {
  RD(x0), RD(x1), RD(x2), RD(x3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6);
}
template <class T0, class T1>
inline void OT(T0 &x0, T1 &x1) {
  OT(x0), OT(x1);
}
template <class T0, class T1, class T2>
inline void OT(T0 &x0, T1 &x1, T2 &x2) {
  OT(x0), OT(x1), OT(x2);
}
template <class T0, class T1, class T2, class T3>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3) {
  OT(x0), OT(x1), OT(x2), OT(x3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);
}
template <class T>
inline void RST(T &A) {
  memset(A, 0, sizeof(A));
}
template <class T0, class T1>
inline void RST(T0 &A0, T1 &A1) {
  RST(A0), RST(A1);
}
template <class T0, class T1, class T2>
inline void RST(T0 &A0, T1 &A1, T2 &A2) {
  RST(A0), RST(A1), RST(A2);
}
template <class T0, class T1, class T2, class T3>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  RST(A0), RST(A1), RST(A2), RST(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);
}
template <class T>
inline void CLR(T &A) {
  A.clear();
}
template <class T0, class T1>
inline void CLR(T0 &A0, T1 &A1) {
  CLR(A0), CLR(A1);
}
template <class T0, class T1, class T2>
inline void CLR(T0 &A0, T1 &A1, T2 &A2) {
  CLR(A0), CLR(A1), CLR(A2);
}
template <class T0, class T1, class T2, class T3>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);
}
template <class T>
inline void CLR(T &A, int n) {
  for (int i = 0; i < int(n); ++i) CLR(A[i]);
}
template <class T>
inline void FLC(T &A, int x) {
  memset(A, x, sizeof(A));
}
template <class T0, class T1>
inline void FLC(T0 &A0, T1 &A1, int x) {
  FLC(A0, x), FLC(A1, x);
}
template <class T0, class T1, class T2>
inline void FLC(T0 &A0, T1 &A1, T2 &A2) {
  FLC(A0), FLC(A1), FLC(A2);
}
template <class T0, class T1, class T2, class T3>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4), FLC(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4), FLC(A5), FLC(A6);
}
template <class T>
inline void SRT(T &A) {
  sort(A.begin(), A.end());
}
template <class T, class C>
inline void SRT(T &A, C B) {
  sort(A.begin(), A.end(), B);
}
const int MOD = 1000000007;
const int INF = 0x7fffffff;
const double EPS = 1e-6;
const double OO = 1e15;
const double PI = acos(-1.0);
template <class T>
inline void checkMin(T &a, const T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkMax(T &a, const T b) {
  if (b > a) a = b;
}
template <class T, class C>
inline void checkMin(T &a, const T b, C c) {
  if (c(b, a)) a = b;
}
template <class T, class C>
inline void checkMax(T &a, const T b, C c) {
  if (c(a, b)) a = b;
}
template <class T>
inline T min(T a, T b, T c) {
  return min(min(a, b), c);
}
template <class T>
inline T max(T a, T b, T c) {
  return max(max(a, b), c);
}
template <class T>
inline T sqr(T a) {
  return a * a;
}
template <class T>
inline T cub(T a) {
  return a * a * a;
}
int Ceil(int x, int y) { return (x - 1) / y + 1; }
inline bool _1(int x, int i) { return x & 1 << i; }
inline int _1(int i) { return 1 << i; }
inline int _U(int i) { return _1(i) - 1; };
inline int count_bits(int x) {
  x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1);
  x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2);
  x = (x & 0x0f0f0f0f) + ((x & 0xf0f0f0f0) >> 4);
  x = (x & 0x00ff00ff) + ((x & 0xff00ff00) >> 8);
  x = (x & 0x0000ffff) + ((x & 0xffff0000) >> 16);
  return x;
}
template <class T>
inline T low_bit(T x) {
  return x & -x;
}
template <class T>
inline T high_bit(T x) {
  T p = low_bit(x);
  while (p != x) x -= p, p = low_bit(x);
  return p;
}
inline void INC(int &a, int b) {
  a += b;
  if (a >= MOD) a -= MOD;
}
inline int sum(int a, int b) {
  a += b;
  if (a >= MOD) a -= MOD;
  return a;
}
inline void DEC(int &a, int b) {
  a -= b;
  if (a < 0) a += MOD;
}
inline int dff(int a, int b) {
  a -= b;
  if (a < 0) a += MOD;
  return a;
}
inline void MUL(int &a, int b) { a = int((long long)a * b % MOD); }
inline int pdt(int a, int b) { return int((long long)a * b % MOD); }
template <class T>
inline void RD(T &x) {
  char c;
  for (c = getchar(); c < '0'; c = getchar())
    ;
  x = c - '0';
  for (c = getchar(); c >= '0'; c = getchar()) x = x * 10 + c - '0';
}
int ____Case;
template <class T>
inline void OT(const T &x) {
  printf("%d\n", x);
}
const int N = 100005;
int A[N], C[N];
int n, nn, last;
void Error() {
  puts("NO");
  exit(0);
}
int main() {
  for (int n____ = int(_RD(n)), i = 0; i < n____; ++i) RD(A[i]);
  if (n & 1) Error();
  sort(A, A + n), nn = -1;
  for (int i = 0; i < int(n); ++i) {
    if (i && A[i] == last)
      C[nn]++;
    else {
      nn++, C[nn] = 1;
      if (i && A[i] != last + 1) Error();
      last = A[i];
    }
  }
  C[1] -= C[0] - 1;
  for (int i = int(1); i < int(nn); ++i) {
    if (C[i] < 2) Error();
    C[i + 1] -= C[i] - 2;
  }
  if (C[nn] != 1) Error();
  puts("YES");
}
