#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> nums(9);
    for (int i = 0; i < n; ++i) {
        int num;
        cin >> num;
        ++nums[num - 1];
    }

    int s = n / 9;

    for (int& a : nums) {
        if (a < s || a > s + 1) {
            cout << "NO";
            return 0;
        }
    }

    cout << "YES";
    return 0;
}