diff --git a/twoSite2SFS.py b/twoSite2SFS.py
new file mode 100644
index 0000000..5f9e21e
--- /dev/null
+++ b/twoSite2SFS.py
@@ -0,0 +1,23 @@
+import sys
+import numpy as np
+
+fn = sys.argv[1]
+if fn == "stdin":
+    fhandle = sys.stdin
+else:
+    fhandle = open(sys.argv[1])
+
+for f in fhandle:
+    if "n" in f:
+        for line in fhandle:
+            N = int(line.split()[0])
+            sfs = np.zeros([N,N,N])
+            break
+    elif "//" in f:
+        print(sfs.flatten())
+    else:
+        toks = f.strip().split()
+        sfs[int(toks[1]),int(toks[2]),int(toks[3])] += 1
+
+
+