我也是QaQ
```cpp
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1005;
int a[MAXN][20];
int f[MAXN];
int main() {
int t, n;
cin >> t;
while (t--) {
cin >> n;
for (int i = 0, m; i < n; ++i) {
cin >> m;
for (int j = 0; j < 20; ++j) {
a[i][j] = 0;
}
for (int j = 0, x; j < m; ++j) {
cin >> x;
a[i][x - 1] = 1;
}
}
for (int i = 0, cnt; i < n; ++i) {
cnt = 0;
for (int j = 0; j < 20; ++j) {
if (a[i][j]) {
++cnt;
} else {
f[i] += cnt;
}
}
f[i] %= 2;
}
int ans = f[0];
for (int i = 1; i < n; ++i) {
ans ^= f[i];
}
if (ans) {
cout << "YES\n";
} else {
cout << "NO\n";
}
}
return 0;
}
```
by GoldenFishX @ 2022-07-22 10:42:29