#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;

    string s[n * 2];
    rep(i,n)cin >> s[i];
    

    sort(s,s+n);
    rep(i,n)s[i+n] = s[i];

    int flag = 1;
    rep(i,n-1){
        
        if(n % 2 == 0){
            if(i+n/2==n)break;
            if(s[i] == s[i+n/2])flag = 0;
        }else{
            if(i+n/2+1 == n)break;
            if(s[i] == s[i+n/2+1])flag = 0;
        }
    }
    if(flag)yn;
    return 0;
}