diff --git a/3/main.py b/3/main.py
new file mode 100644
index 0000000..f0e65aa
--- /dev/null
+++ b/3/main.py
@@ -0,0 +1,55 @@
+import os
+import numpy as np
+
+
+# Find the largest prime factor of 600851475143
+
+
+def isDivisible(n, ms):
+    res = False
+    for m in ms:
+        if n % m == 0:
+            res = True
+            break
+    return res
+
+
+def getNextPrime(ps):
+    if len(ps) == 0:
+        return [2]
+    else:
+        p = ps[-1] + 1
+        while isDivisible(p, [q for q in ps if q < np.sqrt(p)]):
+            p = p + 1
+        ps.append(p)
+        return ps
+
+def findFactors(n):
+    ps = [2]
+    res = []
+    rest = n
+    stop = np.sqrt(n)
+
+    while rest != 1:
+        if rest % ps[-1] == 0:
+            res.append(ps[-1])
+            rest = rest / ps[-1]
+        else:
+            ps = getNextPrime(ps)
+            if stop < ps[-1]:
+                break
+    return res
+
+
+
+def main():
+    print("Hello, this is Patrick")
+
+    number = 600851475143
+    fs = findFactors(number)
+
+    print(max(fs))
+
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file