diff --git a/mm.c b/mm.c
index e3b4924..04fbc18 100644
--- a/mm.c
+++ b/mm.c
@@ -104,8 +104,11 @@ team_t team = {
 
 #define PUT_PTR(p, ptr) (*(unsigned int *)(p) = (unsigned int)(ptr))
 
-#define PRV_FREE(bp) ((char *)(bp))
-#define NXT_FREE(bp) ((char *)(bp) + WSIZE)
+#define PRV_PTR(ptr) ((char *)(ptr))
+#define NXT_PTR(bp) ((char *)(bp) + WSIZE)
+
+#define PRV_BLK(bp) (*(char **)(bp))
+#define NXT_BLK(bp) (*(char **)(NXT_PTR(bp)))
 
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////// STATIC VARS /////////////////////////////////
@@ -134,6 +137,14 @@ static void add_free(void* ptr, size_t size)
 {
   int szClass = getSzClass(size);
   void* classPtr = seg_list[szClass];
+
+  while(classPtr != NULL)
+  {
+    classPtr = NXT_PTR(classPtr);
+  }
+  PUT_PTR(NXT_PTR(classPTR), ptr)
+  PUT_PTR(PRV_PTR(ptr), classPtr)
+  PUT_PTR(NXT_PTR(ptr), NULL);
 }
 
 static void place(void *bp, size_t asize)
@@ -165,13 +176,13 @@ static void* best_fit(void* ptr, size_t asize) {
   unsigned long left_over = GET_SIZE(ptr) - asize;
   void* bestfit = ptr;
   int best_left_over = GET_SIZE(ptr) - asize);
-  while (NXT_FREE(ptr) != NULL) {
+  while (NXT_PTR(ptr) != NULL) {
     left_over = GET_SIZE(ptr) - asize);
     if(left_over<best_left_over){
       best_left_over = left_over;
       bestfit=ptr;
     }  
-    ptr = NXT_FREE(ptr);
+    ptr = NXT_PTR(ptr);
   }
   return bestfit;
 }
@@ -184,8 +195,8 @@ static void* find_fit(size_t asize)
     return NULL;
   } else {
     if (szClass != LISTSIZE -1) {
-    while (NXT_FREE(classPtr) != NULL) {
-      classPtr = NXT_FREE(classPtr);
+    while (NXT_PTR(classPtr) != NULL) {
+      classPtr = NXT_PTR(classPtr);
     }
     return classPtr;
     } else {
@@ -241,8 +252,8 @@ static void *extend_heap(size_t words)
   PUT(FTRP(bp), PACK(size,0)); /* Free block footer */
   PUT(HDRP(NEXT_BLKP(bp)), PACK(0, 1)); /* New epilogue header */
 
-  PUT_PTR(PRV_FREE(bp), 0);
-  PUT_PTR(NXT_FREE(bp), 0);
+  PUT_PTR(PRV_PTR(bp), 0);
+  PUT_PTR(NXT_PTR(bp), 0);
 
   /* Coalesce if the previous block was free */
   return coalesce(bp);