public void solve()
{
int n = sc.Int;
var p = new int[n];
var l = new int[n];
var r = new int[n];
var idx = new int[n];
for (int i = 0; i < n; i++)
{
idx[i] = i;
sc.Multi(out p[i], out l[i], out r[i]);
}
var cmp = compress(p, l, r);
p = p.Select(x => cmp[x]).ToArray();
l = l.Select(x => cmp[x]).ToArray();
r = r.Select(x => cmp[x]).ToArray();
Array.Sort(idx, (i, j) => p[i].CompareTo(p[j]));
var ql = new PriorityQueue <int>((i, j) => l[j].CompareTo(l[i]));
var qr = new PriorityQueue <int>((i, j) => r[j].CompareTo(r[i]));
for (int i = 0; i < n; i++)
{
ql.Push(i);
}
var bit = new BIT(cmp.Count);
long ans = 0;
foreach (var i in idx)
{
while (ql.Count > 0 && l[ql.Top] <= p[i])
{
int x = ql.Pop();
bit.add(p[x], 1);
qr.Push(x);
}
while (qr.Count > 0 && r[qr.Top] < p[i])
{
int x = qr.Pop();
bit.add(p[x], -1);
}
ans += bit.sum(l[i], r[i] + 1);
}
for (int i = 0; i < n; i++)
{
if (l[i] <= p[i] && p[i] <= r[i])
{
--ans;
}
}
Assert(ans % 2 == 0);
Prt(ans / 2);
} // end Solver.solve
static void Main()
{
var s = sc.Str;
int n = s.Length;
var ind = new List <int> [26];
for (int i = 0; i < 26; i++)
{
ind[i] = new List <int>();
}
var bit = new BIT(n);
for (int i = 0; i < n; i++)
{
ind[s[i] - 'a'].Add(i);
bit.add(i, 1);
}
int oc = 0;
var l = new int[26];
var r = new int[26];
for (int i = 0; i < 26; i++)
{
r[i] = ind[i].Count - 1;
if (ind[i].Count % 2 == 1)
{
++oc;
}
}
if (oc > 1)
{
DBG(-1);
return;
}
long sum = 0;
while (true)
{
int min = M, minid = -1;
for (int i = 0; i < 26; i++)
{
if (l[i] >= r[i])
{
continue;
}
int cos = (int)(bit.sum(ind[i][l[i]]) + bit.sum(ind[i][r[i]] + 1, n));
if (cos < min)
{
min = cos;
minid = i;
}
}
if (min == M)
{
break;
}
sum += min;
bit.add(ind[minid][l[minid]], -1);
bit.add(ind[minid][r[minid]], -1);
++l[minid];
--r[minid];
}
Prt(sum);
sw.Flush();
}