static void Main()
{
Console.SetOut(new System.IO.StreamWriter(Console.OpenStandardOutput())
{
AutoFlush = false
});
var h = Read();
var n = h[0];
var a = Read();
var st = new LST <int, int>(n,
(x, y) => x == int.MinValue ? y : x, int.MinValue,
Math.Max, int.MinValue,
(x, p, _, l) => x == int.MinValue ? p : x,
a);
for (int k = 0; k < h[1]; k++)
{
var q = Read();
if (q[0] == 1)
{
st.Set(q[1] - 1, q[2]);
}
else if (q[0] == 2)
{
Console.WriteLine(st.Get(q[1] - 1, q[2]));
}
else
{
Console.WriteLine(1 + st.Aggregate(q[1] - 1, n, n, (p, node, l) =>
{
if (p < n || st.a2[node.i] < q[2])
{
return(p);
}
while (node.i < st.n2 >> 1)
{
node = q[2] <= st.a2[node.Child0.i] ? node.Child0 : node.Child1;
}
return(st.Original(node));
}));
}
}
Console.Out.Flush();
}