diff --git a/zanzibar.py b/zanzibar.py
new file mode 100644
index 0000000..082cc5e
--- /dev/null
+++ b/zanzibar.py
@@ -0,0 +1,14 @@
+t = int(input())
+
+for _ in range(t):
+    sequence = list(map(int, input().split()))[:-1]
+
+    prev_s = 1
+    lb_import = 0
+
+    for s in sequence:
+        if s > (prev_s * 2):
+            lb_import += s - prev_s * 2
+        prev_s = s
+
+    print(lb_import)