#include "bits/stdc++.h"
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x...)
#endif
void solve() {
int n;
string s;
cin >> n >> s;
if (n & 1) {
vector<int> cnteven(26), cntodd(26);
for (int i = 0; i < n; i++) {
if (i & 1) {
cntodd[s[i] - 'a']++;
} else {
cnteven[s[i] - 'a']++;
}
}
debug(cnteven);
debug(cntodd);
bool f = false;
if ((n / 2) & 1) {
for (int i = 0; i < 26; i++) {
if (cnteven[i] & 1) {
cout << "NO\n";
return;
}
if (cntodd[i] & 1) {
if (f) {
cout << "NO\n";
return;
} else {
f = true;
}
}
}
} else {
for (int i = 0; i < 26; i++) {
if (cntodd[i] & 1) {
cout << "NO\n";
return;
}
if (cnteven[i] & 1) {
if (f) {
cout << "NO\n";
return;
} else {
f = true;
}
}
}
}
if (f) {
cout << "YES\n";
} else {
cout << "NO\n";
}
} else {
vector<int> cnteven(26), cntodd(26);
for (int i = 0; i < n; i++) {
if (i & 1) {
cntodd[s[i] - 'a']++;
} else {
cnteven[s[i] - 'a']++;
}
}
for (int i = 0; i < 26; i++) {
if (cntodd[i] != cnteven[i]) {
cout << "NO\n";
return;
}
}
cout << "YES\n";
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
int tests = 1;
cin >> tests;
while (tests--) {
solve();
}
return 0;
}