Program main;
Var
k, n : Integer;
y : real;
Begin
k := 0;
For n := -100 To 100 do
Begin
y := (n * n - 5 * n + 6) / (2 * n - 1);
If (Int(y) = y) Then k := k + 1;
End;
WriteLn('k=',k);
End.