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 ST_RSQ(n);
for (int i = 0; i < n; i++)
{
st.Set(i, a[i]);
}
for (int i = 0; i < h[1]; i++)
{
var q = Read();
if (q[0] == 0)
{
st.Set(q[1], q[2]);
}
else
{
Console.WriteLine(st.Get(q[1], q[2]));
}
}
Console.Out.Flush();
}
static void Main()
{
var r = new List <long>();
var h = Read();
var n = h[0];
var st = new ST_RSQ(n + 1);
for (int i = 0; i < h[1]; i++)
{
var q = Read();
if (q[0] == 0)
{
st.Set(q[1], q[1] + 1, q[2]);
}
else
{
r.Add(st.Get(q[1], q[2] + 1));
}
}
Console.WriteLine(string.Join("\n", r));
}