public static void Solve()
{
var N = Scanner.Scan <int>();
var S = Scanner.Scan <string>().Select(x => 1 << (x - 'a')).ToArray();
var Q = Scanner.Scan <int>();
var seg = new SegTree <int>(S, (x, y) => x | y, 0);
for (var q = 0; q < Q; q++)
{
var query = Scanner.ScanEnumerable <string>().ToArray();
if (query[0] == "1")
{
var(i, c) = (int.Parse(query[1]) - 1, query[2][0] - 'a');
seg.Set(i, 1 << c);
}
else
{
var(l, r) = (int.Parse(query[1]) - 1, int.Parse(query[2]));
var bit = seg.Prod(l, r);
var answer = 0;
for (var i = 0; i < 26; i++)
{
if ((bit >> i & 1) == 1)
{
answer++;
}
}
Console.WriteLine(answer);
}
}
}
public static void Solve()
{
var(N, Q) = Scanner.Scan <int, int>();
var A = Scanner.ScanEnumerable <int>().ToArray();
var seg = new SegTree <int>(A, (a, b) => Math.Max(a, b), -1);
for (var i = 0; i < Q; i++)
{
var(T, X, V) = Scanner.Scan <int, int, int>();
X--;
if (T == 1)
{
seg.Set(X, V);
}
else if (T == 2)
{
Console.WriteLine(seg.Prod(X, V));
}
else if (T == 3)
{
Console.WriteLine(seg.MaxRight(X, v => v < V) + 1);
}
}
}