diff --git a/src/basic.rs b/src/basic.rs
index 5c75209..0176ce8 100644
--- a/src/basic.rs
+++ b/src/basic.rs
@@ -30,7 +30,7 @@ impl<T: Clone> Table<T> {
         &self.data[index]
     }
 
-    fn get_dim(&self, x: usize, y: usize) -> &T {
+    pub fn get_dim(&self, x: usize, y: usize) -> &T {
         self.get(x + y * self.side)
     }
 
diff --git a/src/seed_automation.rs b/src/seed_automation.rs
index 5305c8f..54cafac 100644
--- a/src/seed_automation.rs
+++ b/src/seed_automation.rs
@@ -69,11 +69,13 @@ impl SeedAutomation {
     fn next(&mut self, rng: &mut ChaCha8Rng) {
         let len = (self.world.side * self.world.side) as f32;
         loop {
-            let index = (rng.random::<f32>() * len) as usize;
-            if *self.world.get(index) {
+            let x = rng.random_range(2..14);
+            let y = rng.random_range(2..14);
+
+            if *self.world.get_dim(x, y) {
                 continue;
             }
-            self.world.set(index, true);
+            self.world.set_dim(x, y, true);
             break;
         }
     }