diff --git a/hw1/src/argo.c b/hw1/src/argo.c
index 19ca524..8af68cd 100644
--- a/hw1/src/argo.c
+++ b/hw1/src/argo.c
@@ -26,10 +26,10 @@
  * @return  A valid pointer if the operation is completely successful,
  * NULL if there is any error.
  */
-ARGO_VALUE *argo_read_value(FILE *f) {
+// ARGO_VALUE *argo_read_value(FILE *f) {
     // TO BE IMPLEMENTED.
-    abort();
-}
+    // abort();
+// }
 
 /**
  * @brief  Read JSON input from a specified input stream, attempt to
@@ -51,7 +51,7 @@ ARGO_VALUE *argo_read_value(FILE *f) {
  */
 int argo_read_string(ARGO_STRING *s, FILE *f) {
     // TO BE IMPLEMENTED.
-    abort();
+    abort();    
 }
 
 /**
@@ -94,10 +94,10 @@ int argo_read_number(ARGO_NUMBER *n, FILE *f) {
  * @return  Zero if the operation is completely successful,
  * nonzero if there is any error.
  */
-int argo_write_value(ARGO_VALUE *v, FILE *f) {
+// int argo_write_value(ARGO_VALUE *v, FILE *f) {
     // TO BE IMPLEMENTED.
-    abort();
-}
+    // abort();
+// }
 
 /**
  * @brief  Write canonical JSON representing a specified string
@@ -119,10 +119,10 @@ int argo_write_value(ARGO_VALUE *v, FILE *f) {
  * @return  Zero if the operation is completely successful,
  * nonzero if there is any error.
  */
-int argo_write_string(ARGO_STRING *s, FILE *f) {
+// int argo_write_string(ARGO_STRING *s, FILE *f) {
     // TO BE IMPLEMENTED.
-    abort();
-}
+    // abort();
+// }
 
 /**
  * @brief  Write canonical JSON representing a specified number
@@ -142,7 +142,7 @@ int argo_write_string(ARGO_STRING *s, FILE *f) {
  * @return  Zero if the operation is completely successful,
  * nonzero if there is any error.
  */
-int argo_write_number(ARGO_NUMBER *n, FILE *f) {
+// int argo_write_number(ARGO_NUMBER *n, FILE *f) {
     // TO BE IMPLEMENTED.
-    abort();
-}
+    // abort();
+// }
diff --git a/hw1/src/main.c b/hw1/src/main.c
index 62631ad..c5e1429 100644
--- a/hw1/src/main.c
+++ b/hw1/src/main.c
@@ -23,6 +23,23 @@ int main(int argc, char **argv)
         USAGE(*argv, EXIT_FAILURE);
     if(global_options == HELP_OPTION)
         USAGE(*argv, EXIT_SUCCESS);
+    else if (global_options == VALIDATE_OPTION)
+    {
+        argo_read_value(stdin);
+        return EXIT_SUCCESS;
+    }
+    else if (global_options == CANONICALIZE_OPTION)
+    {
+        ARGO_VALUE *json = argo_read_value(stdin);
+        argo_write_value(json, stdout);
+        return EXIT_SUCCESS;
+    }
+    else if (global_options & PRETTY_PRINT_OPTION)
+    {
+        ARGO_VALUE *json = argo_read_value(stdin);
+        argo_write_value(json, stdout);
+        return EXIT_SUCCESS;
+    }
     // TO BE IMPLEMENTED
     return EXIT_FAILURE;
 }
diff --git a/hw1/src/validargs.c b/hw1/src/validargs.c
index daf4cb2..de4bab8 100644
--- a/hw1/src/validargs.c
+++ b/hw1/src/validargs.c
@@ -40,14 +40,6 @@ int validargs(int argc, char **argv)
             global_options = VALIDATE_OPTION;
             isValid = 1;
         }
-        else
-        {
-            if (parse_arg(*(++ptr)) == -1)
-            {
-                global_options = VALIDATE_OPTION;
-                isValid = 1;
-            }
-        }
         break;
     case 2:
         if (argc == 2)
@@ -57,18 +49,21 @@ int validargs(int argc, char **argv)
         }
         else
         {
-            switch (parse_arg(*(++ptr)))
+            if (parse_arg(*(++ptr)) == 1)
             {
-            case -1:
-                global_options = CANONICALIZE_OPTION;
+                int indented_value;
+                if (argc == 3) {
+                    indented_value = 4;
+                }
+                else {
+                    indented_value = str2int(*(++ptr));
+                }
+                if (indented_value == -1) {
+                    break;
+                }
+                global_options = CANONICALIZE_OPTION + PRETTY_PRINT_OPTION + indented_value;
                 isValid = 1;
                 break;
-            case 1:
-                global_options = CANONICALIZE_OPTION + PRETTY_PRINT_OPTION + str2int(*(++ptr));
-                isValid = 1;
-                break;
-            default:
-                break;
             }
         }
         break;
@@ -123,9 +118,14 @@ int str2int(char *arg)
         }
         else
         {
-            ans = 4;
+            ans = -1;
             break;
         }
     }
-    return ans;
+    if (ans < 256 && ans >= 0) {
+        return ans;
+    }
+    else {
+        return -1;
+    }
 }
\ No newline at end of file