var
n,m,t,i:longint;
ans:array[0..10000] of longint;

procedure add(k:longint);
var
i:longint;
begin
    inc(ans[1],k);
    i:=1;
    while ans[i]>=10000 do begin
        inc(ans[i+1],ans[i] div 10000);
        ans[i]:=ans[i] mod 10000;
        inc(i);
    end;
    if  i>t then t:=i;
end;

procedure cheng;
var
i:longint;
begin
    for i:=1 to t do ans[i]:=ans[i]*2;
    for i:=1 to t do
        if ans[i]>=10000 then begin
            inc(ans[i+1],ans[i] div 10000);
            ans[i]:=ans[i] mod 10000;
        end;
    if ans[t+1]>0 then inc(t);
end;

function dfs(i:longint):int64;
begin
    if i<m then ans[1]:=i*2-1
    else begin
        dfs(i-m+2);
        cheng;
        add((m-2)*2-1);
    end;
end;

begin
    assign(input,'ionah.in');reset(input);
    assign(output,'ionah.out');rewrite(output);
    read(m,n);t:=1;
    dfs(n);
    for i:=1 to t do
        if ans[i]>=10000 then begin
            inc(ans[i+1],ans[i] div 10000);
            ans[i]:=ans[i] mod 10000;
        end;
    if ans[t+1]>0 then inc(t);
    write(ans[t]);
    for i:=t-1 downto 1 do begin
        if ans[i]=0 then write('0000');
        if (ans[i]>0)and(ans[i]<10) then write('000',ans[i]);
        if (ans[i]>10)and(ans[i]<100) then write('00',ans[i]);
        if (ans[i]>100)and(ans[i]<1000) then write('0',ans[i]);
        if (ans[i]>1000) then write(ans[i]);
    end;
    writeln;
    close(input);close(output);
end.