diff --git a/run_via_grpc.py b/run_via_grpc.py
index 1303c6d..c4a14dd 100644
--- a/run_via_grpc.py
+++ b/run_via_grpc.py
@@ -1,3 +1,5 @@
+from time import sleep
+
 import subprocess
 import argparse
 import time
@@ -20,7 +22,14 @@ def main():
     for script in args.ai_files:
         clients.append(subprocess.Popen(["python3", "client.py", script]))
         time.sleep(0.1)
-    server.wait()
+
+    while server.poll() is None:
+        try:
+            time.sleep(0.2)
+        except KeyboardInterrupt:
+            server.kill()
+            for client in clients:
+                client.kill()
 
 
 if __name__ == "__main__":
diff --git a/seekers/game/world.py b/seekers/game/world.py
index d968f20..f4fab9b 100644
--- a/seekers/game/world.py
+++ b/seekers/game/world.py
@@ -40,14 +40,11 @@ def diameter(self) -> float:
     def middle(self) -> Vector:
         return self.geometry / 2
 
-    def torus_difference(self, left: Vector, right: Vector, /) -> Vector:
-        def diff1d(length, a, b):
-            delta = abs(a - b)
-            return b - a if delta < length - delta else a - b
-
-        return Vector(diff1d(self.width, left.x, right.x),
-                      diff1d(self.height, left.y, right.y))
-
+    def torus_difference(self, left: Vector, right: Vector) -> Vector:
+        return Vector(
+            (right.x - left.x + self.width / 2) % self.width - self.width / 2,
+            (right.y - left.y + self.height / 2) % self.height - self.height / 2,
+        )
     def torus_distance(self, left: Vector, right: Vector, /) -> float:
         return self.torus_difference(left, right).length()