diff --git a/2023/20/part 1 solution.py b/2023/20/part 1 solution.py
new file mode 100644
index 0000000..c653e8d
--- /dev/null
+++ b/2023/20/part 1 solution.py	
@@ -0,0 +1,114 @@
+import sys
+from collections import defaultdict, deque
+import math
+
+with open(r'advent_of_code\2023\20\input.txt', 'r') as file:
+    input = file.read()
+
+test_input = r'''broadcaster -> a, b, c
+%a -> b
+%b -> c
+%c -> inv
+&inv -> a'''
+
+another_test_input = r'''broadcaster -> a
+%a -> inv, con
+&inv -> b
+%b -> con
+&con -> output''' 
+
+# input = test_input
+# input = another_test_input
+
+# Read input
+input_data = input
+lines = input_data.split('\n')
+
+# Function to calculate least common multiple
+def least_common_multiple(numbers):
+    result = 1
+    for num in numbers:
+        result = (result * num) // math.gcd(num, result)
+    return result
+
+# Initialize dictionaries
+type_dict = {}
+rules_dict = {}
+
+# Parse input lines
+for line in lines:
+    source, destination = line.split('->')
+    source = source.strip()
+    destination = destination.strip().split(', ')
+    rules_dict[source] = destination
+    type_dict[source[1:]] = source[0]
+
+# Function to adjust type
+def adjust_type(type):
+    if type in type_dict:
+        return type_dict[type] + type
+    else:
+        return type
+
+# Initialize more dictionaries
+from_dict = {}
+inverse_dict = defaultdict(list)
+
+# Adjust types and fill dictionaries
+for x, ys in rules_dict.items():
+    rules_dict[x] = [adjust_type(y) for y in ys]
+    for y in rules_dict[x]:
+        if y[0] == '&':
+            if y not in from_dict:
+                from_dict[y] = {}
+            from_dict[y][x] = 'lo'
+        inverse_dict[y].append(x)
+
+# Initialize variables
+watch = inverse_dict[inverse_dict['rx'][0]]
+low_count = 0 
+high_count = 0
+queue = deque()
+on_set = set()
+previous_dict = {}
+count_dict = defaultdict(int)
+to_lcm = []
+
+# Main loop
+for timestamp in range(1, 1001):
+    queue.append(('broadcaster', 'button', 'lo'))
+
+    while queue:
+        x, from_, typ = queue.popleft()
+
+        if typ == 'lo':
+            low_count += 1
+        else:
+            high_count += 1
+
+        if x not in rules_dict:
+            continue
+        if x == 'broadcaster':
+            for y in rules_dict[x]:
+                queue.append((y, x, typ))
+        elif x[0] == '%':
+            if typ == 'hi':
+                continue
+            else:
+                if x not in on_set:
+                    on_set.add(x)
+                    new_typ = 'hi'
+                else:
+                    on_set.discard(x)
+                    new_typ = 'lo'
+                for y in rules_dict[x]:
+                    queue.append((y, x, new_typ))
+        elif x[0] == '&':
+            from_dict[x][from_] = typ
+            new_typ = ('lo' if all(y == 'hi' for y in from_dict[x].values()) else 'hi')
+            for y in rules_dict[x]:
+                queue.append((y, x, new_typ))
+        else:
+            assert False, x
+    if timestamp == 1000:
+        print(low_count * high_count)
\ No newline at end of file
diff --git a/2023/20/part 2 solution.py b/2023/20/part 2 solution.py
new file mode 100644
index 0000000..91117c6
--- /dev/null
+++ b/2023/20/part 2 solution.py	
@@ -0,0 +1,126 @@
+import sys
+from collections import defaultdict, deque
+import math
+
+with open(r'advent_of_code\2023\20\input.txt', 'r') as file:
+    input = file.read()
+
+test_input = r'''broadcaster -> a, b, c
+%a -> b
+%b -> c
+%c -> inv
+&inv -> a'''
+
+another_test_input = r'''broadcaster -> a
+%a -> inv, con
+&inv -> b
+%b -> con
+&con -> output''' 
+
+# input = test_input
+# input = another_test_input
+
+# Read input
+input_data = input
+lines = input_data.split('\n')
+
+# Function to calculate least common multiple
+def least_common_multiple(numbers):
+    result = 1
+    for num in numbers:
+        result = (result * num) // math.gcd(num, result)
+    return result
+
+# Initialize dictionaries
+type_dict = {}
+rules_dict = {}
+
+# Parse input lines
+for line in lines:
+    source, destination = line.split('->')
+    source = source.strip()
+    destination = destination.strip().split(', ')
+    rules_dict[source] = destination
+    type_dict[source[1:]] = source[0]
+
+# Function to adjust type
+def adjust_type(type):
+    if type in type_dict:
+        return type_dict[type] + type
+    else:
+        return type
+
+# Initialize more dictionaries
+from_dict = {}
+inverse_dict = defaultdict(list)
+
+# Adjust types and fill dictionaries
+for x, ys in rules_dict.items():
+    rules_dict[x] = [adjust_type(y) for y in ys]
+    for y in rules_dict[x]:
+        if y[0] == '&':
+            if y not in from_dict:
+                from_dict[y] = {}
+            from_dict[y][x] = 'lo'
+        inverse_dict[y].append(x)
+
+# Initialize variables
+watch = inverse_dict[inverse_dict['rx'][0]]
+low_count = 0 
+high_count = 0
+queue = deque()
+on_set = set()
+previous_dict = {}
+count_dict = defaultdict(int)
+to_lcm = []
+
+# Main loop
+for timestamp in range(1, 10**8):
+    queue.append(('broadcaster', 'button', 'lo'))
+
+    while queue:
+        x, from_, typ = queue.popleft()
+
+        if typ == 'lo':
+            if x in previous_dict and count_dict[x] == 2 and x in watch:
+                to_lcm.append(timestamp - previous_dict[x])
+            previous_dict[x] = timestamp
+            count_dict[x] += 1
+        if len(to_lcm) == len(watch):
+            print(least_common_multiple(to_lcm))
+            sys.exit(0)
+
+        if x == 'rx' and typ == 'lo':
+            print(timestamp + 1)
+
+        if typ == 'lo':
+            low_count += 1
+        else:
+            high_count += 1
+
+        if x not in rules_dict:
+            continue
+        if x == 'broadcaster':
+            for y in rules_dict[x]:
+                queue.append((y, x, typ))
+        elif x[0] == '%':
+            if typ == 'hi':
+                continue
+            else:
+                if x not in on_set:
+                    on_set.add(x)
+                    new_typ = 'hi'
+                else:
+                    on_set.discard(x)
+                    new_typ = 'lo'
+                for y in rules_dict[x]:
+                    queue.append((y, x, new_typ))
+        elif x[0] == '&':
+            from_dict[x][from_] = typ
+            new_typ = ('lo' if all(y == 'hi' for y in from_dict[x].values()) else 'hi')
+            for y in rules_dict[x]:
+                queue.append((y, x, new_typ))
+        else:
+            assert False, x
+    if timestamp == 1000:
+        print(low_count * high_count)
\ No newline at end of file