> Program p1006;
> Const
>   infile = 'p1006.in';
>   outfile = 'p1006.out';
> Var
>   n, p, e, i, d, j: Longint;
> Begin
>   Assign(input, infile);
>   Assign(output, outfile);
>   Reset(input);
>   Rewrite(output);
>   n:=0;
>   Readln(p, e, i, d);
>   While not ((p=-1) and (e=-1) and (i=-1) and (d=-1)) Do Begin
>     Inc(n);
>     For j:=0 To 644 Do
>       If (i+33*j-p>=0) and (i+33*j-e>=0) and ((i+33*j-p) mod 23 = 0) and ((i+33*j-e) mod 28=0) Then Break;
>     while i+33*j-d<=0 Do j:=j+644;
>     Writeln('Case ', n, ': the next triple peak occurs in ', i+33*j-d, ' days.');
>     Readln(p, e, i, d);
>   End;
>   Close(input);
>   Close(output);
> End.