program Rvl;
var all,n,m,z :integer;
    f1,f2:text;
begin
assign(f1,'TREE.DAT');
read(f1,n,m);
close(f1);

readln(n,m);
z:=n;
all:=n;
while (z<>m) or not(z>m) do begin z:=z+n-1; all:=all+n; end;

assign(f2,'TREE.SOL');
if z>m then write('mishtch') else write(all);
close(f2);
end.