diff --git a/day09.py b/day09.py
index 19c9bf3..5092aa3 100644
--- a/day09.py
+++ b/day09.py
@@ -6,39 +6,28 @@ TEST_SOLUTION_PART1 = 127
 TEST_SOLUTION_PART2 = 62
 
 
-class NumberCruncher:
-    def __init__(self, preamble):
-        self.buffer = []
-        self.preamble = preamble
-
-    def addNumber(self, number):
-        self.buffer.append(number)
-        if len(self.buffer) > self.preamble:
-            self.buffer = self.buffer[1:]
-
-    def isValidNextNumber(self, number):
-        if len(self.buffer) < self.preamble:
-            return True
-
-        for combination in itertools.combinations(self.buffer, 2):
-            if sum(combination) == number:
-                return True
-
-        return False
-
-
 def part1(test_mode=False):
     my_input = aoclib.getInputAsArray(day=DAY, return_type=int, test=test_mode)
     if test_mode:
-        cruncher = NumberCruncher(5)
+        preamble = 5
     else:
-        cruncher = NumberCruncher(25)
+        preamble = 25
 
-    for i in my_input:
-        if not cruncher.isValidNextNumber(i):
-            return i
+    number_buffer = []
+    for number in my_input:
+        if len(number_buffer) == preamble:
+            found_sum = False
+            for combination in itertools.combinations(number_buffer, 2):
+                if sum(combination) == number:
+                    found_sum = True
+                    break
 
-        cruncher.addNumber(i)
+            if not found_sum:
+                return number
+
+        number_buffer.append(number)
+        if len(number_buffer) > preamble:
+            number_buffer = number_buffer[1:]
 
     return 0