diff --git a/includes/push_swap.h b/includes/push_swap.h
index 5d78d7a..43a7f10 100644
--- a/includes/push_swap.h
+++ b/includes/push_swap.h
@@ -6,7 +6,7 @@
 /*   By: tmaze <tmaze@student.42.fr>                +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2019/02/21 14:13:53 by tmaze             #+#    #+#             */
-/*   Updated: 2019/03/16 13:32:59 by tmaze            ###   ########.fr       */
+/*   Updated: 2019/03/20 12:24:09 by tmaze            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -51,7 +51,7 @@ void				ps_rrerot(t_psdata *data);
 int					is_op(char *buff);
 t_list				*add_op(t_psdata *data, char *op);
 int					get_params(t_psdata *data, int ac, char **av, int viz);
-int					check_input(char *in, int *ret);
+int					check_input(t_psdata *data, char *in, int *ret);
 
 void				mark_groups(t_psdata *data);
 t_stack				*get_last_a(t_psdata *data);
diff --git a/srcs/checker.c b/srcs/checker.c
index b364729..8720924 100644
--- a/srcs/checker.c
+++ b/srcs/checker.c
@@ -6,7 +6,7 @@
 /*   By: tmaze <tmaze@student.42.fr>                +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2019/02/23 13:35:15 by tmaze             #+#    #+#             */
-/*   Updated: 2019/03/19 16:44:06 by tmaze            ###   ########.fr       */
+/*   Updated: 2019/03/20 12:26:46 by tmaze            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
diff --git a/srcs/ps_stktools2.c b/srcs/ps_stktools2.c
index 4f70179..d11a2d4 100644
--- a/srcs/ps_stktools2.c
+++ b/srcs/ps_stktools2.c
@@ -6,7 +6,7 @@
 /*   By: tmaze <tmaze@student.42.fr>                +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2019/02/25 12:44:08 by tmaze             #+#    #+#             */
-/*   Updated: 2019/03/18 15:13:10 by tmaze            ###   ########.fr       */
+/*   Updated: 2019/03/20 12:27:42 by tmaze            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -22,9 +22,10 @@ void	ps_initdata(t_psdata *data)
 	data->viz = '\0';
 }
 
-int		check_input(char *in, int *ret)
+int		check_input(t_psdata *data, char *in, int *ret)
 {
 	int		i;
+	t_stack	*ptr;
 
 	i = 0;
 	if (in[i] && ft_issign(in[i]))
@@ -32,7 +33,16 @@ int		check_input(char *in, int *ret)
 	while (in[i] && ft_isdigit(in[i]))
 		i++;
 	if (in[i] == '\0' && ft_hasdigit(in) && ft_atois(in, ret))
+	{
+		ptr = data->a;
+		while (ptr)
+		{
+			if (*ret == ptr->nb)
+				return (0);
+			ptr = ptr->next;
+		}
 		return (1);
+	}
 	return (0);
 }
 
@@ -48,7 +58,7 @@ int		get_params(t_psdata *data, int ac, char **av, int viz)
 	{
 		if (i == 1 && viz && ft_strcmp(av[i], "-v") == 0)
 			data->viz = 'a';
-		else if (check_input(av[i], &nb) && (new = ps_stknew(nb)) != NULL)
+		else if (check_input(data, av[i], &nb) && (new = ps_stknew(nb)) != NULL)
 		{
 			new->ind = 0;
 			ps_stkpsh(data, 'a', new);
@@ -60,7 +70,7 @@ int		get_params(t_psdata *data, int ac, char **av, int viz)
 			return (0);
 		}
 	}
-	return (1);
+	return (ac != 1);
 }
 
 int		is_op(char *buff)