diff --git a/ga1_last.py b/ga1_last.py
new file mode 100644
index 0000000..979fef7
--- /dev/null
+++ b/ga1_last.py
@@ -0,0 +1,29 @@
+import random
+
+def calc(A):
+    n = len(A)
+    res = 0
+    for i in range(0,n):
+        for j in range(i+1, n):
+            res += A[j] - A[i]
+    return res
+
+def calc2(A):
+    n = len(A)
+    res = 0
+    for i in range(0,n):
+        res += (2*(i+1)-n-1)*A[i]
+    return res
+
+def main():
+    for i in range(0,100):
+        A = []
+        for j in range(0,i):
+            A.append(random.randint(0,1000000))
+        if not calc(A) == calc2(A):
+            print("wrong!")
+            return
+    print("ok!")
+
+if __name__ == "__main__":
+    main()