diff --git a/homeworks/23_Plamen_Tsokov/checkCircles.py b/homeworks/23_Plamen_Tsokov/checkCircles.py
new file mode 100644
index 0000000..b884221
--- /dev/null
+++ b/homeworks/23_Plamen_Tsokov/checkCircles.py
@@ -0,0 +1,27 @@
+from math import sqrt
+
+def check_Circles(c1_c, c1_r, c2_c, c2_r):
+    if(c1_c == c2_c and c1_r == c2_r):
+        return "Matching"
+    c1_x, c1_y = c1_c
+    c2_x, c2_y = c2_c
+
+    distance = sqrt((c2_y - c1_y)**2 + (c2_x - c1_x)**2)
+
+    if(c1_r + c2_ < distance):
+        return "not intersecting"
+    if(c1_r + c2_r == distance):
+        return "touching"
+    if(c1_r + c2_r > distance):
+        if(distance + c1_r <= c2_r):
+            if(c1_r + distance == c2_r):
+                return "Circle B contains circle A and they are touching"
+            else:
+                return "Circle B contains circle A"
+        elif(distance + c2_r <= c1_r):
+            if(c1_r == c2_r + distance):
+                return "Circle A contains circle B and they are touching"
+            else:
+                return "Circle A contains circle B"
+        else:
+            return "Intersecting"
diff --git a/homeworks/23_Plamen_Tsokov/replace.py b/homeworks/23_Plamen_Tsokov/replace.py
new file mode 100644
index 0000000..a353865
--- /dev/null
+++ b/homeworks/23_Plamen_Tsokov/replace.py
@@ -0,0 +1,16 @@
+#zadacha 3#
+def replace(list, find, replace1):
+	a = 0
+	for i in list:
+		if (type(i) != int) and (len(i) > 1):
+			list2 = list[a]
+			replace(list2, find, replace1)
+		if i == find:
+			list[a] = replace1
+		a = a +1 
+	return list
+
+list = [ 'a', 1, [ ['a', 'b'], 1], ([1, 3, 'a'], 'b')]
+res = replace(list, 'a', 'c')
+print(res) # => [ 'c', 1, [ ['c', 'b'], 1], ([1, 3, 'c'], 'b')]
+
diff --git a/homeworks/23_Plamen_Tsokov/stairclimb.py b/homeworks/23_Plamen_Tsokov/stairclimb.py
new file mode 100644
index 0000000..48e2676
--- /dev/null
+++ b/homeworks/23_Plamen_Tsokov/stairclimb.py
@@ -0,0 +1,13 @@
+#zadacha 2#
+while True:
+	N = int(input("stair count: "))
+	if N >= 2:
+		break
+
+def num_ways(N):
+  if N < 2:
+    return 1
+  return num_ways(N-1) + num_ways(N-2)
+
+print(num_ways(N))
+