BIKM PASCAL

program BIKM;
var i, j, n, maxx, k:longint;
    a,d:array[0..10000000]of longint;

procedure nhap;
var i:longint;
begin
    readln(n,k);
    for i:=1 to n do readln(a[i]);
end;

procedure giai;
var i:longint;
begin
    maxx:=-1;
    for i:=1 to k+1 do
    begin
        inc(d[a[i]]);
        if d[a[i]]>1 then
            if a[i]>maxx then maxx:=a[i];
    end;
    for i:=2 to n-k do
    begin
        inc(d[a[i+k]]);
        dec(d[a[i-1]]);
        if (d[a[i+k]]>1) then
            if a[i+k] > maxx then maxx:=a[i+k];
    end;
    writeln(maxx);
end;

begin
    assign(input,'BIKM.inp');reset(input);
    assign(output,'BIKM.out');rewrite(output);
    nhap;
    giai;
end.