diff --git a/test/3/2.py b/test/3/2.py
index d6ed205..d48a3a5 100644
--- a/test/3/2.py
+++ b/test/3/2.py
@@ -3,9 +3,6 @@ a = int(n.split('-')[1])  # 暴力取出小数位数和精度
 i = 1
 s = 0
 while (1 / (2 * i - 1) >= 10**(-a)):  # 精度要求作为条件
-    if (i % 2 == 0):
-        s -= 1 / (2 * i - 1)
-    else:
-        s += 1 / (2 * i - 1)
+    s += (-1)**(i % 2 + 1) / (2 * i - 1)
     i += 1
 print(("{:." + str(a) + "f}").format(s * 4))