no

include <bits/stdc++.h>

using namespace std;

int main()
{
int n;
cin >> n;
cout << 2*n;
}

Hiiiiiiii

tấm chiếu mới .-.

:))))))))))))))))))))))))))

include <bits/stdc++.h>

using namespace std;
int n, m, a[1000005], res, d[1000005];
int main() {
cin >> n >> m;
for ( int i = 1; i <= n; i++ ) {
cin >> a[i];
d[a[i]]++;
}
sort ( a + 1, a + 1 + n );
for ( int i = n; i >1; i-- ) {
res=res+ upper_bound ( a + 1, a + i, m - a[i] )-a-1;
}
cout<<res;
}

L

include <iostream>

using namespace std;
int main()
{
int i;

cin >> i;
long p[i], q[i];
for (int j = 0; j < i; j++)
{
    cin >> p[j];
}
for (int j = 0; j < i; j++)
{
    if (p[j] < 4 || p[j] % 2 == 1)
    {
        cout << "-1"<<endl;
        break;
    }
    if(p[j]%4==0)
    cout<<p[j]*p[j]/16<<endl;
    else cout<<(p[j]/4)*(p[j]/4+1)<<endl; 
}
return 0;

}