diff --git a/1st.py b/1st.py
old mode 100644
new mode 100755
diff --git a/ga1_last.py b/GA1/ga1_last.py
old mode 100644
new mode 100755
similarity index 100%
rename from ga1_last.py
rename to GA1/ga1_last.py
diff --git a/GA2/sum_of_three.py b/GA2/sum_of_three.py
new file mode 100755
index 0000000..df04391
--- /dev/null
+++ b/GA2/sum_of_three.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+
+import sys
+
+def search_two(A, sum2, i_skip):
+    i = 0
+    j = len(A) - 1
+
+    while i < j:
+        if i == i_skip:
+            i = i + 1
+        elif j == i_skip:
+            j = j - 1
+        else:
+            cs = A[i] + A[j]
+            if cs == sum2:
+                return True
+            elif cs > sum2:
+                j = j - 1
+            else:
+                i = i + 1
+
+    return False
+
+def sum_of_three(A, sum3):
+    A.sort() # assume using mergesort for worst case of O(n*log(n))
+    l = len(A)
+
+    for i in range(l):
+        if search_two(A, sum3 - A[i], i):
+            return True
+
+    return False
+
+if __name__ == "__main__":
+    args = [int(x) for x in sys.argv[1:]]
+    print(sum_of_three(args[1:], args[0]))
+
diff --git a/heapsort.py b/heapsort.py
old mode 100644
new mode 100755
diff --git a/mergesort.py b/mergesort.py
old mode 100644
new mode 100755
diff --git a/pair_equal.py b/pair_equal.py
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new mode 100755
diff --git a/partition.py b/partition.py
old mode 100644
new mode 100755