diff --git "a/\354\244\221\354\262\251\355\225\250\354\210\230.py" "b/\354\244\221\354\262\251\355\225\250\354\210\230.py"
new file mode 100644
index 0000000000000000000000000000000000000000..03c7d7f54c9ec443f5bc549acefc9bde64f74241
--- /dev/null
+++ "b/\354\244\221\354\262\251\355\225\250\354\210\230.py"
@@ -0,0 +1,21 @@
+import math
+def stddev(*args):
+    def mean():
+        return sum(args) / len(args)
+    def variance(m):
+        total = 0
+        for arg in args:
+            total += (arg - m) ** 2
+        return total / (len(args)-1)
+    v = variance(mean())
+    return math.sqrt(v)
+
+print(stddev(2.3, 1.7, 1.4, 0.7, 1.9))
+print(stddev(1,2,3))
+
+# print(stddev(1))
+# ZeroDivisionError
+
+# print(mean(1,2))
+# NotDefined
+