Add another defer exercise

exercises/116_defer3.zig

@@ -0,0 +1,18 @@
+//
+// When there are multiple defers in a single block, they are executed in reverse order.
+//
+const std = @import("std");
+
+pub fn main() void {
+    var x: u32 = 100;
+    {
+        // Try reordering the statements to get the answer 42
+        defer x = x / 10;
+        defer x = x + 11;
+        defer x = x * 2;
+
+        // It might seem silly in this example, but it's important to know when
+        // deinitializing containers whose elements need to be deinitialized first.
+    }
+    std.debug.print("{d}\n", .{x});
+}

patches/patches/116_defer3.patch

@@ -0,0 +1,14 @@
+--- exercises/116_defer3.zig	2026-05-31 22:29:56.189323732 +0200
++++ answers/116_defer3.zig	2026-05-31 22:30:17.749186667 +0200
+@@ -7,9 +7,9 @@
+     var x: u32 = 100;
+     {
+         // Try reordering the statements to get the answer 42
+-        defer x = x / 10;
+-        defer x = x + 11;
+         defer x = x * 2;
++        defer x = x + 11;
++        defer x = x / 10;
+
+         // It might seem silly in this example, but it's important to know when
+         // deinitializing containers whose elements need to be deinitialized first.

src/elrond.zig

@@ -1223,6 +1223,10 @@ const exercises = [_]Exercise{
         .main_file = "115_packed2.zig",
         .output = "",
     },
+    .{
+        .main_file = "116_defer3.zig",
+        .output = "42",
+    },
     .{
         .main_file = "999_the_end.zig",
         .output =