CAFE PASCAL

var n,k,kq:int64;

procedure nhap;
begin
    read(n,k);
end;

function tinh(v:int64):int64;
var mu,s:int64;
begin
    mu:=1;s:=0;
    while v >=mu do
        begin
            s:=s+(v div mu);
            mu:=mu*k;
        end;
        exit(s);
end;

procedure xuly;
var d,c,t,s:int64;
begin
    d:=1;c:=n;
    while d<c do
        begin
            t:=(d+c) div 2;
            s:=tinh(t);
            if s>=n then
                c:=t
            else d:=t+1;
        end;
    kq:=d;
    write(kq);
end;

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