diff --git a/generator.c b/generator.c
index 0b2df47..553204b 100644
--- a/generator.c
+++ b/generator.c
@@ -123,17 +123,17 @@ struct Graph *parse(int argc, char *argv[])
 				fprintf(stderr, "[%s] An edge consists of two "
 						"nodes separated by a dash\n", pname);
 				free(str);
-				exit(EXIT_FAILURE);
+				return NULL;
 			}
 			switch (src) {
 			case -2:
 				free(str);
-				exit(EXIT_FAILURE);
+				return NULL;
 				break;
 			case -1:
 				fprintf(stderr, "%s\n", edge);
 				free(str);
-				exit(EXIT_FAILURE);
+				return NULL;
 				break;
 			default:
 				break;
@@ -141,6 +141,7 @@ struct Graph *parse(int argc, char *argv[])
 
 			count++;
 		}
+		free(str);
 	}
 
 	struct Graph *graph = createGraph(V+1);
@@ -176,9 +177,21 @@ int main(int argc, char *argv[])
 	sigaction(SIGINT, &sa, NULL);
 	sigaction(SIGTERM, &sa, NULL);
 
+	struct Graph *graph;
+
 	while (quit == 0) {
-		struct Graph *graph = parse(argc, argv);
+		graph = parse(argc, argv);
+		if (graph == NULL) {
+			for (int i = 0; i < graph->V; i++) {
+				free(graph->array[i].head);
+			}
+			free(graph->array);
+			free(graph);
+			exit(EXIT_FAILURE);
+		}
 		printGraph(graph);
+		free(graph->array);
+		free(graph);
 		break;
 	}