diff --git a/test/3/1.py b/test/3/1.py
new file mode 100644
index 0000000..ce457bc
--- /dev/null
+++ b/test/3/1.py
@@ -0,0 +1,5 @@
+n = int(input())
+s = 1
+for i in range(n):
+    s *= (i + 1)
+print(s)
diff --git a/test/3/2.py b/test/3/2.py
new file mode 100644
index 0000000..d6ed205
--- /dev/null
+++ b/test/3/2.py
@@ -0,0 +1,11 @@
+n = input()
+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)
+    i += 1
+print(("{:." + str(a) + "f}").format(s * 4))
diff --git a/test/3/3.py b/test/3/3.py
new file mode 100644
index 0000000..6127354
--- /dev/null
+++ b/test/3/3.py
@@ -0,0 +1,5 @@
+n = int(input())
+a = [0, 1]
+for i in range(2, n + 1):
+    a.append(a[i - 1] + a[i - 2])  # 递推
+print(a[n])
\ No newline at end of file
diff --git a/test/3/4.py b/test/3/4.py
new file mode 100644
index 0000000..2efd92f
--- /dev/null
+++ b/test/3/4.py
@@ -0,0 +1,10 @@
+n = int(input())
+a = list(map(int, input().split()))
+for i in range(n):
+    for j in range(i + 1, n):
+        if (a[j] < a[i]):
+            ls = a[i]
+            a[i] = a[j]
+            a[j] = ls
+for i in range(n):
+    print(a[i], end=" ")