diff --git a/lib.h b/lib.h
index bebc1df..1831f5e 100644
--- a/lib.h
+++ b/lib.h
@@ -2,12 +2,13 @@
 #define LIB_H
 
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 typedef struct State
 {
   // Sandpiles
-  unsigned char *data;
+  uint64_t *data;
   size_t dwidth;
 
   size_t window_len;
diff --git a/main.c b/main.c
index 0a8e97a..c863e01 100644
--- a/main.c
+++ b/main.c
@@ -17,12 +17,11 @@
 
 void step(state_t *state)
 {
-  state->data[((state->dwidth / 2) * state->dwidth) + (state->dwidth / 2)]++;
   for (size_t i = 0; i < state->dwidth; ++i)
     for (size_t j = 0; j < state->dwidth; ++j)
       if (state->data[(i * state->dwidth) + j] >= 4)
       {
-        unsigned char *references[] = {
+        uint64_t *references[] = {
             (j == 0) ? NULL : &state->data[((i)*state->dwidth) + j - 1],
             (i == state->dwidth - 1)
                 ? NULL
@@ -33,8 +32,8 @@ void step(state_t *state)
             (i == 0) ? NULL : &state->data[((i - 1) * state->dwidth) + j]};
         for (size_t k = 0; k < 4; ++k)
           if (references[k])
-            *references[k] += 1;
-        state->data[(i * state->dwidth) + j] = 0;
+            *references[k] += state->data[(i * state->dwidth) + j] / 4;
+        state->data[(i * state->dwidth) + j] %= 4;
       }
 }
 
@@ -97,8 +96,8 @@ int main(void)
     for (size_t i = 0; i < state.dwidth; ++i)
       for (size_t j = 0; j < state.dwidth; ++j)
       {
-        Color c                = {0};
-        unsigned char sandpile = state.data[(i * state.dwidth) + j];
+        Color c           = {0};
+        uint64_t sandpile = state.data[(i * state.dwidth) + j];
         if (sandpile == 0)
           c = BLACK;
         else if (sandpile == 1)